With a new baby on the way, Jimmy Kimmel and his wife, Molly McNearney, recently went in for an ultrasound, and things did not go as planned.

Kimmel shared some home video footage of his wife's trip to the obstetrician on Monday's Jimmy Kimmel Live. The sweet family moment all went downhill when the host's long-time "mortal enemy," Matt Damon, walked through the door.

Despite his promise to stop having sex with Kimmel's wife, Damon claimed he's the one who got McNearney pregnant and came up with the perfect way to figure out who gets to be the dad: let the baby decide.

Watch: Matt Damon and Jimmy Kimmel Burst Out Laughing at Couples Therapy

Leaning down next to the mom-to-be's baby bump, Damon spoke to the baby in dulcet tones and laid out the options.

"Hello baby! We don’t know if you're a boy or a girl, but you have a choice of daddies," Damon...