Leo's obvz not a one-woman man, and Rihanna is probz four five seconds from wildin' (because all of her kindness is taken for weakness).

RadarOnline.com is reporting that the 40-year-old actor was spotted making out with a blonde model at 1Oak nightclub in Los Angeles over the weekend -- in front of the 26-year-old singer.

“Rihanna was at the owner Richie Akiva’s table downstairs,“ a source dishes. “Leo was at a separate table. He had his own by the DJ booth.“ Rihanna and Leo were rumored to be an item after they were spotted kissing at the Playboy mansion last month.

I say this all the time, but it bears repeating. Date regular guys, famous women. They pull all kinds of dumb stuff, but not this kind of dumb stuff. They would cut off their face before losing you.