Blueface Wipes Balls With Towel Before Throwing It Into Crowd

Blueface went a little nuts in what he offered fans last night as a souvenir ... with the rapper throwing a towel that he had just wiped his balls with into a crowd.

The shirtless rapper made the crude move at L.A.'s Belasco Theater ... wiping sweat from his forehead before plunging the rag into his shorts.

Then he tossed the towel into the crowd ... where one woman triumphantly grabbed the ... umm, let's call it ... free merch.

We reported earlier ... Blueface was streaming when he attended Skilla Baby's concert Saturday night in the DTLA venue.

While his team was recording ... former boxer Adrien Broner appeared to slump over on a couch, leading EMT workers to treat him.

He was later carried downstairs by his pals and placed into a wheelchair ... before one of the EMT workers helped him into a car.