Actor Gerard Butler and actress Olivia Munn during an interview with host Jay Leno on December 3, 2012. Credit: Paul Drinkwater/NBC/NBCU Photo Bank

There's no doubt Gerard Butler is a ladies' man!

While telling stories from his travels Monday, Dec. 3, on The Tonight Show, Butler mentioned his "girlfriend" twice, which caught host Jay Leno's attention.

"You mentioned this girlfriend twice," Leno said. I've never heard you do that . . . give me a little information on this. Can I ask you how long you've been going out?"

"It's been seven months now . . . it's not a record," Butler, 43, joked.

The Playing for Keeps actor dating actress/model Madalina Ghenea, but he wouldn't comment any further.

Butler then met Leno's second guest, actress Olivia Munn, for the first time -- and got a little flirty!

Munn, 32, told a story to Leno about about a motorcycle accident that resulted in a scar on her leg. "She still has great legs though, huh?" Butler said.

Leno later showed a very sexy photo of The Newsroom actress in Vanity Fair posing by a pool. Butler joked, "Pool party [at] Olivia's house."