Bi-Back Mountain(2006)

War is hell for Ian and Jake in Iraq until a moment of passion takes them away from it all for just one night. The fling is short lived though because Ian is scheduled to ship out and is going home to marry his fiance‚ Shy Love. A year later when a postcard arrives from Jake the two military men have a reunion that change them forever. When Jake arrives at Ian and his wife's ranch he's brought along T.J. Hart, a city girl who realizes there is more to the guy's friendship than they are letting on. After catching up over a few drinks T.J. dares Ian and Shy to kiss because she thinks they are such a hot couple. Soon both couples shed their inhibitions and Jake and T.J. have sex across the room from Ian and Shy, who are going at it, too.