Floyd Mayweather REJECTED a male teenage fan's request for a selfie at the Clippers game over the weekend ... and it's all 'cause his nails were painted.
TMZ Sports has learned a young fan was hoping to get a snap with Floyd after the Clippers vs. Grizzlies game at Staples Center on Saturday ... so he hopped on the court to approach him, but was shut down immediately after Mayweather got a glimpse of his nails.
"You got painted nails, I don't take pictures with guys with no painted nails," Floyd is heard saying in the video as his body guard gets the fan to back up.