Remember Nate Naylor, Scarlett Johansson's boob-obsessed ad exec boyfriend? Two months ago he sucker-punched a romantic rival at a bar, then ran away and hid in a bathroom. But the damsel in question wasn't ScarJo; it was one of Nate's exes.

Working the holiday party circuit on a week night in December, a handful of Naylor's acquaintances (and extended acquaintances) met up at Von, a bar in the East Village. Nate would have been three months into his relationship with Scarlett at the time.

Naylor arrived after midnight, and ran into an ex-girlfriend and her new boyfriend. With nary a word exchanged, a witness tells us that Naylor "sucker punched the dude," bloodying the man's nose. Amid shouts, Naylor fled to a bar bathroom and locked himself in. "Security eventually coaxed him out and ejected him," the witness says.

Though noticeably smaller than ScarJo's "Morrissey in his prime" boyfriend, the punch victim did not seek medical attention. He merely cleaned himself up and returned to drinking his beer.

Nate Naylor has yet to respond to our request for comment.

Have you witnessed Nate Naylor's fists of fury and/or cowardice? Email maureen@gawker.com.

[Image by Jim Cooke, photos via Getty and Pal2iyawit/Shutterstock]