Will Arnett: Shirtless Six Pack Abs for 'Up All Night' Promo!

Will Arnett shows of his amazing six-pack abs in just a pair of boxer-briefs in this new promo for the new season of Up All Night!

The 42-year-old actor is pictured alongside his co-star Christina Applegate, who plays a working mother married to a stay-at-home dad (Arnett) in the NBC comedy.

Will recently split with his wife of nine years, Amy Poehler.

“Will looks really good right now. Everybody is talking about how cut he is,” a source told Us Weekly. “He’s been working out and his skin is really great.”

Make sure to catch the season premiere of Up All Night on NBC tonight (September 20) at 8:30/7:30c!

Christina has also been keeping busy with her own business venture! She recently launched FabKids.com, which is a new children’s apparel brand and e-commerce site. Go check it out!

Bigger picture inside…