Friend is heartbroken what went wrong ?

Posting for a friend possible trigger inside so please forgive also no very fluent in English


I have a friend....I'll just call her A and she likes a guy X. They known each other for awhile now X was really into A always calling, texting her, taking her to dinners etc but A just wasn't sure about a boyfriend at that time in her life. After some time A told me that she decided she might finally want to give her and X a try I hinted this to X he seemed generally happy so I got him to ask A out to dinner so they could talk. The next day A looked very sad and confused I asked her what was wrong and A said the dinner didn't go the way she had hoped. A told me that sex came up in there convo and A told X about her past relationships. After that X started avoiding A out of nowhere for days now (and isn't like him he always gives A an morning text and tries to make plans with her fairly often) so I did some digging and found out X got back from a trip with his friends (he doesn't know that like 80% of his "friends" are childhood friends of mine lol) and that he has been spending a lot of time with this girl that went as well...will call her B. I did some more research and B some girl from X's hometown and (apparently X has been holding hands with B,talking with her a lot even were kissing once etc). A has been very upset and crying all day and keeps saying stuff like she wishes she wasn't such a slut in her past (she thinks it was her number that intimated X ) I've been trying to cheer her up for awhile now and begged her not to say such things..... X and A were finally gonna get together and suddenly this b!%$h comes from nowhere hasn't seen X in 3 years probably and pretty much steals X from A

Why did he pull away

Was he just a wimp because of her number of partners ?