sex by proxy
This occurs when someone with whom you have recently had sex also recently had sex previously with a "third party". You are then said to have had sex with third party by proxy.
Jim: Hey, Ted, you know that Julie chick you were bangin' last night? Ted: "Yeah"
Jim: Man, she has been doing that nasty dred locked gansta, Willie, for a month.
Ted: So?
Jim: Ah Man, you had sex by proxy with the dred man.
Jim: Man, she has been doing that nasty dred locked gansta, Willie, for a month.
Ted: So?
Jim: Ah Man, you had sex by proxy with the dred man.
sex proxy
One with whom your sexual partner has had sexual relations with.
After his girlfriend confessed all to him, my buddy Hans found out he has a dog for a sex proxy!