Okay so im on a two day skiing trip with my gf her sister and her sisters bf (sisters bf is also one of my close friends). And so this guy walks into the chalet and the sisters are just start commenting on him and long story short i guessed that he was my gfs ex, which he was.

Then her sister starts telling her boyfriend about them but whispering, so i start getting pissed off and ask them to tell me which they dont. Eventually my buddy wants to leave and get his snowboard, and im really pissed at my gf for not telling me when everyone else now knows, so i leave and go with him, on the way he tells me what her sister said to him which was blah blah they went out for two weeks and liked each other alot. THIS ISNT WHAT I WAS MAD ABOUT! When i go into a relationship i assume right off of the bat that the woman has loved other men and had sex with them, i dont expect f-ing virgin maries in every relationship, i dont get jealous about that shit, i was mad that she wasnt even frikken telling me.

Of course to make things worse she didnt even seem to notice or care that i was mad which made things worse, but eventually i talked to her about it and we're pretty good now, but seriously, was i justified in being mad at her about that?

Yes.

No, it has nothing to do with you. If she wanted to talk about him, then she would talk about it. Some dogs are better left sleeping.

*sigh* youre right as usual Euda, i apologised to her for it today =/