Am I over reacting? It annoys me that my roommate's boyfriend makes these comments.?

My roommate/bestfriend and I sometimes joke around like "Oh you look so hot tonight I want to make out with you." We don't really mean it. We both like men only. Her fianc� frequently chimes in with "Oh my god that'd be hot can I watch?" and sometimes makes comments on his own about how hot it would be to see us together. It makes me feel AWKWARD!!! Isn't that inappropriate? Or since we joke around does that give him the okay to? It's just like HELLO your fianc� doesn't want you to talk about me being included in any of your bedroom activities!!! She's never said anything, to me or him (as far as I know) about it though, but to me it's weird and awkward! Am I over reacting?