Confused

Both of my ex got into it last week and one threaten the other because he kept on harassing me constant calling texting creating fake accounts and all . I felt bad he got threaten and told him sorry I didn’t know the other ex was going to do that and i can’t control what anybody does I didn’t even know he was going to contact him I was venting.

Any way with that being said I do not want to be non contacted by my first ex for the rest of my life I can’t file a restraining order I didn’t think of it before I’m 21 I have a lot of growing to do any advice?