A person, who formally being homosexual, converts back to heterosexuality, but then is lured back to the other side, once more becoming homosexual.
"It's such a damn shame... we got him back onto the straight and narrow, but he had to attend that swinger party the other night. Some fella applied some pressure, and once again, he's licking the other side of the stamp"
When you find someone doing porn who looks just like a friend, but said friend insists it isnt her rubbing one out on her webcam (though it probably really is)
"Hey is this (insert whatever porn website mysteriously popped up on your computer) you"
"No!"
"Are you sure?"
"Yes! It must be my dopplebanger. Why are you looking at asian porn?"
"Um.... got to, I have a phone call. fapfapfapfapfap"