The guy doing the situps in the speedo is Michael Brandon. He's a favorite of mine. >:D
You may want to try hxxp://www.wtule.net the Gay Erotic Video Index. You can search for actors, movies and studios. Michael Brandon's filmography is pretty big, so it may take you some time to find the film from the clips….unless someone knows it right off hand.
thank you for the clue.. but I haven't find out the movie