Ben Affleck looks jet-lagged while on a Seine River trip in Paris.

Ben Affleck slept on a Paris boat with Jennifer Lopez and their kids

The 49-year-old actor was napping on the boat's deck with his lips open on July 23.

He rested his head and feet on a rail at times and crouched at others.

Ben Affleck falls asleep during a cruise along the Seine River in Paris on July 23. He was joined by wife Jennifer Lopez, her twins Max and Emme, and his daughters Violet and Seraphina. (Best Image/ BACKGRIest Image/ BACKGRID) 

Ben's tiredness isn't surprising given jet lag; Los Angeles is 9 hours behind Paris.

Bennifer have been busy since landing on July 21: they had a late-night terrace supper at Le Matignon, then visited the Musée Dorsay and had another dinner on July 22.

The couple were also spotted shopping and snapping photos after the museum trip, maximizing their time in the City of Love.