VIDEO: Serena visits Letterman, sings with 'Orange Is the New Black' stars

David Letterman is a longtime tennis enthusiast, hosting a range of professional stars on his Late Show over the years, including Novak Djokovic on Tuesday. Last night, Serena Williams sat down beside the venerable host for a chat—and, earlier, a hit in the street. (Indeed, see below: Serena goes so far as to smash a deli store's window.)

The world No. 1 talked about her love for tennis and what keeps her going in the sport now, in what has to be called the twilight of her career. (The answer: Chasing records.)

She also spoke to her doubles prowess, the pros and cons of playing mixed dubs, and that one time sister Venus hit her in the back with a serve:

Elsewhere in their lengthy sit-down conversation, Letterman spontaneously reached for Serena's exposed midriff as if to poke it with a finger. "You wanna touch me?" Serena said, ever-so-slightly surprised. The two proceeded to exchange tummy touches, which led to awkward belly laughs in the audience. "Ooh, me likey!" Serena said after putting a hand on the host's midsection. Seeing is believing:

Serena, sporting sky-high heels, a black crop top, and a painted-on white skirt, also took to the street and hit a few shots with Dave on a makeshift court before they opted to try to break a store window:

It's a busy week for Williams, who also sang karaoke this week at the Delta Open Mic event held at New York City's Arena venue. She performed a singles take on "Diamonds Are A Girl's Best Friend," replete with a bit choreography. Serena was joined by Jack Sock and entertainers Kathy Griffin, Laverne Cox, Uzo Aduba, and Darren Criss at the event. Here's Aduba's image of her and Orange Is the New Black co-star Cox with Serena at the shebang:

[Thanks to commenter @tennisfan2331 for the tip on Serena and Dave's "belly laughs" clip.]

What song would you have Serena warble on a scareoke stage?

Got a tip or a point to make? Hit me on Twitter at @jonscott9.