Lonesome Cowboys (1968)

In the wild wild west, Ramona Alvarez and her perpetually stoned nurse run into five gay cowboys. The seven members of the party desire a handsome male drifter, except for the transvestite sheriff, who can't be bothered about anything but his outfit. All hot & bothered at this point, the cowboys rape Ramona, who subsequently has sex with the drifter and, in the afterglow of sex, wants to form a suicide pact with him. The drifter rejects her new desire and rides off into the sunset with another man.