<human>: We only saw each other for about 2-3 months. We were never official. There's a post in my recent history where I asked r/askwomen how to deal with clingy best girl friends but now I'm looking into it more and I think they might actually be dating. About 1.5 weeks ago he said he wanted to be just friends again which is cool and I'm OK with that. It wasn't really serious.           
             
Anyway, I was browsing around on twitter and instagram and I stumbled on her profile while looking at mutual friends and friend activity. It really seems like she's either dating him or severely in love with him. There are a lot of pictures of them together with tags like #luhhhim #bae things that the common social media girl tags boyfriends with. She will mention the things they do together and things he buys her, etc. And of course, that they are dating (when I confronted him about it he said she was just jealous). But honestly it really gives me that vibe that they are dating. Which is cool and all again, but I feel really bad for her because if they are dating, she had every right to be upset at me and act like a bitch because I was cheating with her boyfriend! I feel like I couldn't trust him to begin with so I feel like this is the reason why. I don't know. I feel terrible and like I need to tell her what happened. But what if they aren't dating? Would providing picture proof of what she posts and says help figure it out? Should I just message her and ask? I don't know if I should even say anything.

Can you succinctly summarize the text in 1-3 sentences?
<bot>: was sleeping with a guy with a close girl friend, now I think she might be his girlfriend and I feel the need to tell her but am unsure.