Request by Undertale_Is_Alive
Ok, I don't know If i made this clear in the chapter or not but in this Error saves Ink from an abusive relationship with Nightmare like the request asked. But I also added some of Nightmare cheating with Cross. If you don't Crossmare, Uh... Maybe this part isn't for you? Just a warning.

Ink POV
I sobbed as Nightmare beat me to the ground.
"Get home on time next time you whore." He said.
I tried to get up but he pinned me to the ground.
"Please don't." I begged, still sobbing.
He ignored me and proceeded to take off my clothes.
After he was done with what I hate to call pleasuring himself with me he pulled me close to him.
"I love you." He mumbled.
I knew it was a lie. I knew he didn't. But when he said that it made it so hard to leave him.
I got dressed and walked to our friend, Error's house. He's the only one I feel I can talk to to get my mind off of the abuse I suffer.
I carefully knocked on the door, my face still wet and stained with tears.
When he opened it he immediately helped me inside and got the first aid kit.
"What did he do to you this time?" He asked.
He hated Nightmare. I can only hope he doesn't hate me. I mean, if I weren't here he wouldn't have to worry.
I didn't answer his question. He cleaned the cuts and bandaged them.
"Ink, I really really think you should break up with him." He said.
I started crying.
"I can't... he says he loves me..." I cried.
"We both know he's lying. Ink, anyone who harms you... who makes you feel unsafe and trapped... they don't care for you." He said. "I know it's hard... I know you think you can't leave but you can... I hate seeing you like this. You're the most kindest and sweetest person I've ever met please... for your sake and mine leave him."
I hugged Error. He hesitated but hugged back.
"Thank you for listening..." I said.
He sighed.
"Be safe..."
I walked home in the rain and when I walked in I saw Nightmare making out with Cross. They stood up and Nightmare pushed me to the ground and punched me until I bled. Cross kicked me repeatedly and cut my face and legs. I was screaming. I began crying and ran to the basement.
I can't live like this anymore! I grabbed a knife and finally decided it was time to end my pain.

Error POV
I noticed Ink had forgot her phone here. I decided to teleport to her and give it to her personally. I want to see her again.
I have had a crush on her since Nightmare introduced me. She had the brightest most genuine smile and the most amazing personality.
But, not even a week into their relationship Ink started talking to me about how he constantly insulted her and hit her.
I felt angry and horrified that he'd to that to such an amazing person. And a month in Ink caught him cheating with Cross and sometimes Killer. They'd even help him beat her sometimes.
I teleported to Ink and was about to scream when I saw her about to slit her throat. I grabbed the knife from her and she broke down.
I held her in my arms as she sobbed and silently screamed in agony. I took hold of the knife and wet upstairs, murdering Nightmare and Cross. Ink watched the whole thing and didn't even say a word.
"Ink... I know this isn't a good time but... I love you. Like, actually love you... I'd never harm you-"
She kissed me.
"I trust you." She sobbed.
I took her home and healed her.
"...thank you... I owe you my life." She said.
"You owe me nothing." I told her.