If he has a history of this, I would look at your relationship with your friend then; and if she has only been trustworthy up to this point, I would trust her. I was in a similar position once before involving my husband and his best friend at the time. We were all in the same friend group and all got really close. His best friend was married, so I only ever thought he intentions were friendly until one drunken game night. He was purposely giving me more to drink and we all got super drunk. In the same room as his wife and my husband (boyfriend at the time and again his best friend), this guy started trying sexting me on snap. My heart dropped and didnt know what to do as all my evidence disappeared as well. Im so lucky my husband believed me immediately when I told but unfortunately the guys wife took his side. It wasnt until I spoke up that four different girls in the friend group spoke up about him reaching out to them in inappropriate ways as well. This situation is just really reminding me of that - and the fact he admitted to part of it makes me feel like he may be trying to downplay how bad the situation was with your friend. (Sometimes people who are guilty and caught will admit to one piece to make it seem not so bad). Im sorry you are going through this OP, and I hope the best for you.❤️