BF told me there was a girl from his game flirting with him, I got pretty excited since he is the monogamous one in our relationship and this kind of thing never happened before. I even helped him come up with a pick up line.

The same night we met up and he shared a couple parts of the chat with me.

Thing is, he didn't act like he was single, but as if he had a (monogamous) gf and their interactions were as if they were doing something wrong/forbidden that his gf would be upset about.

There was even stuff like: "your GF doesn't go through your phone right?" and she asking him to delete her pics (not nudes, just selfies) "in case his gf sees it."

I mean she even asked "what do you consider cheating?" and he did not take the opening to explain what his relationship was like!

So I got upset for him "leading on" the girl and interacting like they were heading into emotional cheating or something.

I told him that, and his reasoning was that he wouldn't actually pursue anything (saying again that he is monogamous) so he didn't want to tell her as not to seem like he was actually interested, and to keep things from progressing further.

He also said he was very private and doesn't like telling people that his relationship is open and even said he doesn't like that I tell too much people (I just don't hide it, and people close to me eventually find out since something relevant always end up coming up in conversation).

I don't even know what I want to get from this post, it seems like I'm making a big deal of a small situation and I guess what really upset me in the end was that his justifications of not telling seemed like he was embarassed of having an open relationship.