When two men have so much sex that the receiving partners cheeks get stuck together from the dried man juice like two piece of metal that have been welded. Also a manufacturing term.
Guy: Last night I was with Brian and I Butt Welded him.
Other Person: What is that?
Guy: I came really hard and after I pulled out, he didn't wash his cheeks properly so the next morning his butt crack was stuck shut.
Other Person: I am your Grandmother, why would you tell me about Butt Welding?
more severe than beer goggles. the holder of the welders mask is the person who hooks up with the most unattractive female after consuming mass quantities of alcohol
did you see the girl that jon hooked up with? damn he had the welding mask on last night
Dick welding: The act of having hardcore ball slapping sex. Then pulling out and cumming from the top of the vagina to the bottom welding it together with your cum. After deciding not to cum in her pussy.