Sharon Stone Shoots Down Rumors She's Dating 25-Year-Old Rapper RMR

Sharon Stone is hilariously denying she's dating rapper RMR ... and we say hilarious because she couldn't stop laughing when a photog raised the rumor about her and the 25-year-old.

Sharon was out Thursday in Beverly Hills with her son, Roan, when paps asked whether it's true she's dating the up-and-coming artist. You gotta see the reaction from Sharon and her 21-year-old son. Lots of 😂😂😂 .

The actress straight up says she's NOT dating the rapper ... and Roan even tells the photog, "You couldn't have asked a funnier question."

Now, the reason it's even been a rumor is because she was photographed last month at an L.A. club with RMR ... and not just hanging with him, but wearing one of his trademark face masks.

Based on her reaction in this video ... we'd say those pics were nothing more than a friendly photo op for RMR.

BTW ... one other thing Sharon did not find quite as funny was what happened to one of the photogs shooting her. Dude wiped out hard, but Sharon kept a straight face, and was actually super gracious.