Was these friends girls or guys??? Im going to tell you my motto: "There is no such things as platonic friendship's between guys and girls." This is a truth most people dont want to hear but it needs to be said. Givin the chance (like if the girl said lets have sex to the guy) any guy (unless he's some sorta holy type person like a buddist monk) would bang there closest friend thats a girl. I dunno why your women would want to cause tension in your relationship she would have been able to tell you were upset from your body language. It is messed up she didnt even offer to have you go with her , isnt being in a commited relationshp supposed to be sharing lifes experiences with each other? She has come home in the wee hours of the night? That is a horrible sign bro , you need to really have a long talk with her and truly sort out these issues or break up with her...