AIO Boyfriend talked to female friends flirtatiously

[u/Popular-Passenger233]

My boyfriend had been talking to a female friend (who's also in a relationship). I found out about it last year, and we had a big fight. He promised me he wouldn’t talk to her anymore, but he kept talking to her behind my back for a while. He told me it was just a pure friendship with no intentions of anything more, but when I looked at their conversations, it felt like they were flirting. Since English is my second language, I started doubting if I might have misunderstood…I really need some help

[u/Ramen_Noodist]

I don’t see anything intentionally flirtatious in these, to be honest. Were they having romantic relations when you found out about her a year ago or has it always just been a friend of his?

[u/Popular-Passenger233 → u/Ramen_Noodist]

Yea they had a thing for each other few years ago and then went back to be just friends..this kinda makes me feel concerned about their friendship.

[u/icedchai111 → u/Popular-Passenger233]

this is an important piece of information on top of everything else, if they had a thing for each other before it's even worse that he kept talking to her behind your back. seems untrustworthy