This is where the man takes a thin shirt and puts it over his cock before fucking a woman, and everytime he inserts himself, he slowly let's the shirt go deeper. Must be taken out before too deep. Can be done with pants as well.
Some guy: What did you do with your girlfriend last night?
Some other guy: We were shirt fucking.
When two or more people are wearing the same shirt
DAMMIT TOM you are really shirt fucking me today you knew i was going to wear that