I think I saw it around 2004. I vaguely remember the woman reached out to one of the brothers first, she reached her hand in his pants. I don't remember what happened after that, but somewhere close to the end the woman had to go somewhere on a boat/cruise? with the other brother, so the one she was with at the beginning struggled with all these sexual fantasies about his woman and his brother on the boat in which he basically gone paranoid. Anyone?
The movie is Double Impact starring Jean Claude Van Damme and Jean Claude Van Damme. He plays twins separated at birth one becomes a Pilates or yoga instructor and the other becomes a mid level gangster in Hong Kong. The meet up for some reason and try to take down the man responsible for the death of their parents. The gangster has a blonde girlfriend. For some reason the Yoga brother ends up on a boat with the girlfriend. Nothing happens but she is topless and hanging her clothes on a line. Meanwhile the mobster brother is getting drunk and imagining his brother and girlfriend having sex. Then he fights his brother because of this. Bolo Yeung was also in this who you may remember from Bloodsport and Enter the Dragon and many other martial arts movies.