Rihanna and Ryan Phillippe romping around?

Amidst his now-forgotten fling with Amanda Seyfried, Ryan Phillipe reportedly was cozying up to a different lady: Rihanna.

According to Us Weekly, the actor, 36, and Grammy-winning songstress, 23, first hooked up back in December “when things were strained” with Rihanna’s ex-boyfriend, L.A. Dodger Matt Kemp.

The two reconnected this month — and things got pretty steamy after a fashion event in Los Angeles on Feb. 12.

“She thinks he’s hot,” a source told Us Weekly. “They totally had sex [that night]. And it wasn’t even the first time.”

Phillippe even attended RiRi’s 23rd birthday party at her Beverly Hills home last week. Though the two spent time together, they “were discreet,” said a source, adding, “It is still very casual.”