It's long but I just needed to get it off my chest

Update: we saw his lawyer and they offered him a FANTASTIC plea deal so he decided to take it. His lawyer told us that even with me testifying he would get a rape charge so now it's only sexual assault and 10 years probation.

In short, my cousin (15 at the time) and I (17 at the time) were staying at my grandma's house and she decided to leave because she wanted to go hang out at Walmart (I live in a small town, that's what we do on the weekends 😂) well she called me saying she wanted me to come up there with her and the other people there so I did. We met some of our friends and they had some alcohol so of course us being us, decided we wanted to drink some. Well we decided to go home but we weren't done hanging out with everyone so we went back to her house (her mom was out of town) with (let's call him C) and another one of his friends. She wanted C in her room because she outright told me she wanted to have sex with him when she was 100% sober. Well one thing lead to another her and C had sex. Well our grandma woke up and couldn't find us so she drove to my cousins house and saw the cars outside so she came in. I was on the couch chilling with the other guy while my cousin and C were in her room. My grandma went back and found my cousin and C having sex. Well of course the cops were called and all of that, my cousin FAKED being passed out because she didn't tell C that she was only 15 and didn't want to be caught having sex with a 20 year old guy.

Fast forward a year, I'm 18, cousin is 16, C is 21 looking at a 20 year prison sentence because he had "raped" a minor while she was "passed out drunk". I completely cannot agree that he raped her, I know better. I saw C at the gas station about a month and a half ago, we talked and decided to go out to eat and try to figure out what to do after I told him I knew she was lying . I decided that I think I should testify on his behalf that he did not rape her. We started hanging out more and now we are together. We've talked about it all several times just to see if he changes his story about it all, he doesn't. I really feel bad because if I do this I will lose most of my family because my grandma and my cousin's mom are the ones pushing for him to go to prison. Not my cousin and not anyone else. My whole family believes he done this.

One another note me and him are together. I was just playing around on his phone one day because mine died and I saw screenshots of messages from right after this all happened between him and my cousin and she said "I know you didn't rape me, I didn't know what to do but I promise I'm not going to let them say you raped me." Here we are one year later and she still hasn't come forward that she's lying.

We go talk to his lawyer in the morning about everything and I am so hoping that I can bring up those messages.