So we aren't together anymore but his bestfriend wants...

So literally a week ago I broke up with the guy I'd been with for a year and a half. Now during our relationship shit was really bad he was abusive and I blamed myself so when someone was nice to me of course I got attached well back in March I got black out drunk and slept with his bestfriend he still doesn't know and never will because there's no need to add to his pain and regret. Well he pushed me to the edge when I woke up at 2:00am and him and his car were gone and I had a friend take me to his co workers house and sure enough he was staying the night there...didn't say anything to me just left the bed in the middle of the night because "he couldn't sleep" yeah I was devastated and still kinda am but it's getting better because haha the girl doesn't want him lmao she told him it can never work lol that's what he gets. Well same night he gets told this I just so happened to be talking to his other bestfriend on snapchat...yeah well we were talking as friends and by 9:30 nudes were happening and yeah either way I'm not sure how to feel or what to do because honestly his co worker and I were friends so I don't think it's wrong because I should be allowed to talk to whomever I want. Right? But still I need your guys input because I don't know what to do. ****Please if you're going to comment something rude expect to get the same attitude right back not in the mood to put up with crap.