Inyoung You, a 21-year-old woman charged with involuntary manslaughter in connection with her boyfriend’s suicide, pleaded not guilty Friday as prosecutors revealed several "abusive" text messages she sent in the months leading up to his death.

"do everyone a favor and go fucking kill yourself, you’re such a fucking stupid ass worthless shit," You texted 22-year-old Alexander Urtula in April.

Four days before Urtula's death, You texted him, "FUCK YOU GO FUCKING KILL YOURSELF..."

You, a former Boston College student from South Korea, appeared in Suffolk Superior Court in Boston for the first time Friday since she was indicted for Urtula's death. You had withdrawn from the college in August and was living in South Korea.

Urtula killed himself on May 20, hours before he was set to attend his graduation ceremony at Boston College along with his parents and brother. You was present when Urtula killed himself.

Prosecutors alleged that You was “physically, verbally, and psychologically abusive” toward Urtula during their year-and-a-half relationship and that the abuse “intensified" in the days and hours leading to Urtula’s death.

You’s alleged abuse was witnessed by the couple’s friends and classmates at Boston College and was documented in the more than 75,000 text messages the couple exchanged in the two months prior to Urtula’s death, prosecutors said. You sent more than 47,000 of those texts.

"I'll go die for you.... whatever will make you happy," Urtula wrote in one text message to You in April.

You’s “abuse was the cause of Urtula’s suicide,” Suffolk County Assistant District Attorney Caitlin Grasso said in court Friday. You's alleged abuse “overwhelmed” Urtula’s will to live and she failed to prevent his death, Grasso said.

You's bail was set at $5,000 and she was ordered to surrender her passport and stay in Massachusetts. She was escorted from the court in handcuffs.

Starting in late March, You repeatedly texted Urtula to “go kill yourself” and “go die,” and told him that her life, his family’s life, and the world would be better off without him, prosecutors said.

"do everyone a favor and go fucking kill yourself, you’re such a fucking stupid ass worthless shit. dude just fucking do everybody a favor and go fucking kill yourself honestly. Fucking WORTHLESS ASS FUCKING PIECE OF SHIT U DESERVE NOTHING IN THE FUCKING WORLD," she wrote to Urtula in April.

Prosecutors said their case will show how You “isolated” Urtula from his friends at Boston College and how she used threats of self-harm and suicide to "control" and “own” him while also urging him to repeatedly harm or kill himself.

Steven Kim, You’s attorney, condemned Suffolk County District Attorney Rachael Rollins for “unjust and callous behavior” in the “cheap pursuit of headlines.”

In a statement Friday, Kim slammed the district attorney for branding “an emotionally fragile young woman a monster to the entire world, further traumatizing her.”

Kim described Urtula and You as “two emotionally needy young adults whose relationship had become a toxic blend of need, anger, fear and love.”

“They simultaneously faced the everyday pressures all post-adolescents encounter from family, friends, social media, college life, and the things young people try to navigate every day,” Kim said.

“And they lived their lives on their phones in a way that is hard for many of us to understand.”

You and Urtula began dating sometime in late 2017 or early 2018 after meeting through the Philippine Society of Boston College. Prosecutors said You allegedly became abusive toward Urtula in the late summer of 2018 after discovering that he had not been truthful about communicating and meeting with his ex-girlfriend, who was also a Boston College student.

Their text messages showed the “power dynamic” of the relationship where the couple discussed how You “owned” Urtula and was her “slave” and that he had “ceded his autonomy” to her, prosecutors said.

In a text to You in April, Urtula wrote:

“you own me…all of me...only you...you have complete control of me emotionally and physically… and you dictate my happiness...you owning all of me includes everything…what I think, what I feel…you own all of that. All of my history…everything...anything you want I want to give it to you. Your happiness is my only priority.” (4/1/2019, 12:01 am)

Prosecutors alleged that You became fixated on Urtula’s upcoming graduation ceremony and the possibility of him interacting with his other friends in college, including his ex-girlfriend.

Four days before his death, You texted Urtula:

“All it is gonna take at graduation is for someone to come up to you and pull you aside or come running to you and hugging you and you will just fucking do everything again to disrepsect me and break your promise FUCK YOU AND GO FUCKING KILL YOUSELF AND EVERYONE IN THAT TOXIC GROUP THEY ALL DESERVE TO FUCKING DIE" (5/16/2019, 1:28 PM)

Prosecutors alleged that You used graphic threats of harming and killing herself to get Urtula to do something she wanted him to, or if he didn’t immediately respond quickly to her texts or calls or; expressed a need for space during an argument; or said he was going to sleep.

Two days before his death, You texted Urtula:

“u can’t figure it out? u wanna make me livid again? u want me to slash my throat? Is that what you want? Like why do I have to threaten my own fucking life for u to finally do something? Did I NOT FUCKING TELL U TO READ [MY TEXT] NOW IF YOU DO NOT FUCKING READ IT RIGHT NOW I’M LITERALLY GOING TO FUCKING SLASH MY THROAT AND TAKE A VIDEO SAYING IT WAS BECAUSE OF YOU AND THAT I WANT YOU TO SEE IT IS THAT WHAT YOU FUCKING WANT YOU IDIOTIC WORTHLESS FUCKING SHITHEAD is that what you want? I have to fucking threaten my life for u to listen to me?...you literally end up doing what I fucking want at the end of the day so why try to fight me?” (5/18/2019, 1:25 pm)

She also threatened Urtula that she would kill herself and blame him for her death in a social media post or a suicide note.

Prosecutors said Friday that their witnesses will testify that Urtula couldn’t end the relationship because he was concerned that You would hurt or kill herself.

“[Urtula] felt trapped ... like he had no option but to stay with her because her life was literally in his hands,” Grasso said, quoting a witness.

Urtula repeatedly told You in text messages that he would do anything, including kill himself, to make her happy.

“Inyoung please I’ll give you whatever you want...I’ll leave this fucking earth just please don’t do anything don’t hurt yourself anymore...so please I’ll get out of your life I’ll go die like you want… I’ll erase myself from this world...It’ll probably be better off and I don’t have anything anymore anyways if I don’t have you...I’ll go die...please I’ll do whatever you want...you own me...I’ll literally do whatever you want...please just don’t fucking hurt yourself anymore...Please...I’ll go die for you...whatever will make you happy” (4/11/19, 11:39 p.m.)

Last December, Urtula texted two of his friends saying, “I’m worried, I need help. I can’t do this alone.”

When one of the friends contacted the campus health center’s emergency services hotline on behalf of Urtula, he was told there was no imminent danger, prosecutors said.

Prosecutors described Urtula as “driven” and “strong-willed” with no history of mental health problems before his relationship with You.

Urtula’s journal entry in March showed the impact the relationship had on his mental health, prosecutors said.

“She attacks my self-worth...whenever we argue it always reverts back to the past and how I lied and hurt her before and how she doesn’t believe that it won’t happen again. Then I when I agree to end it because she says she’s done with me because I’m a ‘horrible retarded fuck up that is just a burden on everyone’s life,’ she in turn threatens to kill herself because of me.” (3/26/2019)

Prosecutors alleged that You failed to stop Urtula’s suicide even though she knew his GPS location 55 minutes before his death. He had also texted her his intention to kill himself that morning.

You did not call law enforcement or medical professionals to intervene before Urtula’s death, prosecutors said, making her “criminally responsible” for his suicide.

Before her arraignment, You’s defense team released copies of text messages to the Boston Globe to show that she had tried to stop Urtula from killing himself the morning of his death.

When You realized what Urtula planned to do, she sent dozens of texts to Urtula, pleading with him to “stop,” “don’t do this” and “don’t leave me like that,” the Globe reported.

On the morning of his death, Urtula texted You, “I’m not talking to anyone. I won’t ever again. I’m happy I got to spend my last night with you. I love you inyoung until my last breath.”

He also texted her saying it wasn’t her fault, it was “mine.”

“What,” You texted him. “What. UR LEAVING ME”

In a series of messages with typos and capital letters, You urged Urtula to stop, the Globe reported.

“ALEX. WHAT SRE YOU [expletive] DOING. IF U [expletive] LOVE ME STOP. IF U EVER [expletive] LOVED ME STOP.”

"PLWASE STOp,” she wrote. “Talk to me. STOP. STOP. PLESEE. IM CRYING PLEASE. PICK UP. PLEASE . . . DON’T LEAVE ME LIKE THAT. IF U EVER LOVED ME STOP. IF YOU WANNA SHOW ME U LOVE ME STOP . . . please pick up . . . talk to me please.”

When Urtula turned on his GPS, You tracked his location and texted Urtula's brother the location. She took an Uber to his location while sending him texts telling him she was on her way and asking him to wait for her, the texts showed.

"Please baby,” You wrote in one text sent to the Globe. “i love you so much. Please stop please. Please baby please stop i love you.”

Another text said, “IM BEGGING YOU. PLEASE IM ALMOST THERE PLEASE. where are u please please please.”

You eventually reached the location where Urtula was and was there minutes before he killed himself.

“All of us, including Inyoung You, mourn Alexander Urtula," Kim, You's attorney, said in a statement after her arraignment Friday.

"But further punishing a young woman who loved him only compounds the tragedy and tarnishes the memory of that young man," he said.

The case has drawn parallels to the Michelle Carter trial in Massachusetts. Carter, now 22, is currently serving a 15-month jail sentence after she was convicted of involuntary manslaughter for encouraging her boyfriend — through text messages — to kill himself.

Massachusetts lawmakers recently introduced a bill criminalizing suicide coercion with jail time of up to five years. The bill, called Conrad's law, is named after Carter's boyfriend, Conrad Roy.

The bill proposes that a person who is aware of "another person's propensity for suicidal ideation" can be punished for "coercing or encouraging" them to kill themselves.

In 2017, suicide was the second-leading cause of death in the US for people between the ages of 10 to 34, according to the Centers for Disease Control and Prevention.

Kim, You's attorney, said Friday that authorities should be looking for better ways to support young people in such situations instead of prosecuting them.

“It is unfathomable that this DA’s office is using precious public resources to dangerously broaden the homicide laws in an attempt to capture headlines by painting a one-sided, incendiary portrait of an innocent 21-year-old student when hundreds if not thousands of serious violent crime cases with actual victims are going unsolved,” Kim said.

"Since losing Alexander in May, the Urtula family and everyone who loved Alex has been devastated by his loss," David Guarino, a spokesperson for the Urtula family, said in a statement. "Not a minute of any day goes by without those who loved Alex grieving and continually feeling the sharp pain of his passing all over again."

Natana J. DeLong-Bas, a Boston College professor and one of Urtula's instructors, told BuzzFeed News that he had a "zest for life."

"I remember him as energetic, enthusiastic, and always looking to the future," she said. "I hope that is how people will remember him -for how he lived, not how he died."