Floyd Mayweather -- Strippers Got $3,000 Each ... For Instagram Twerk-fest

Floyd Mayweather shelled out $30k to get 10 strippers into his hotel suite for a crazy Instagram twerk video ... and he handpicked the women from a popular L.A. strip club ... TMZ Sports has learned.

The video blew up on social media Monday night when Floyd posted the 10-on-1 video to Instagram ... and the ass community went wild.

Now we've learned Floyd hired all of the women off the floor of Sam's Hofbrau Adult Cabaret in Los Angeles ... and forked over $3,000 per stripper.

We're told the women were hired to dance for an hour in Floyd's penthouse suite at a fancy L.A. hotel -- but some stayed later because Floyd had all sorts of food and drinks in the room.

But get this ... we're told there's a beef behind the scenes, because the women at Sam's who didn't get picked to twerk for Floyd are steaming mad ... and it's made for some serious tension at the office.

Strippers -- they have feelings too.