Cambridge Dictionary defines "thwarting" as the action of a gay male putting his testicles into a another gay male's anus and deliberately attempting to catch HIV; or, when a gay male puts his entire mouth, teeth and all, into the anus, to eat out the HIV.

In the case of gay thwart sex incest, it is combined with convential homosexual fornication, between blood-related family members.

This is a fact, according to Yahoo Answers user Billie - a general practitioner of 38 years.

successfully completing a task or not

To put a stop to, cease, halt; usually of a plan deemed faulty.

The act of interfering with someone trying to hook up, get some action, or generally get in the way of some play.

The aftermath of being cock blocked.

The unisex term for cockblock / twat swat. The act of blocking sexual advances or a turn-off.