this "friend" is suspicious.. think she wants my man!

Hi, well, currently I have 3 years with my man (no married just being couple) and we have a 2 couples of married friends that we met last year in a party. We've been hanging around since and everything goes well but since we met one couple specifically, things are weird. The girl of that relationship, seems to be attracted to my boyfriend. How do I know? Well, the body language never lie! And of course she is married and everything, but that is not a limitation when it comes to be attracted to someone else. The point here is, my boyfriend doesn't sees that and one day I told him what I felt about her, and he told me I'm overreacting and I'm jelous... I tried to convince myself that he's right, but you know, there's something telling me she is not a good friend... Right now I'm in another country working, so we are in a long distance relationship, and he keeps going out with her and the couples... I've been seeing the photos they upload in facebook  when they go out, and it's pretty funny that every single one, they appear close or together, or doing something together, they two... Not even with his husband, but with my boyfriend. Am I being paranoid or should i do something?