The movie came out in the early 80s.  Set in 1980s California.  American or Canadian.  2 young men are house sitting for a producer or director. They decide to impersonate him and hold a casting call at the house.  Many young women show up for the fake casting call.  A guy who is gay shows up who was hired unseen as an assistant shows up believing one of them to be the director.   In part of the plot they discover some type of gangsters are after the director and they go after the young man impersonating the director.  The head assassin is voluptuous femme fatale.  The assistant ends in a sword fight with her, slowly picking off pieces of clothing.  When he disrobes her he says something to the effect of “At times like this, I wish I were a lesbian.”