When you find a penis that is an exact match to your own. Like twins separated at birth, but attached to a different person.
I was giving head to this guy, and it felt like i had seen his dick somewhere before . I realized it was MY dick. If i suck my doppledonger, isnt that like giving myself head?
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"