The "Backdraft" star insists there are no firm plans for the model and Justin Bieber to celebrate their rumoured recent wedding, but he's already thinking about taking a stranger as his date when the invite arrives.
Refusing to confirm or deny reports suggesting the pop star and his fiancee have secretly tied the knot, Uncle Willy tells TMZ he has dreamed up a scheme to turn any family bash the couple might throw into an opportunity to make money for a good cause.
"I wanna auction off, like raffle, on the Internet, like, 'Be Billy Baldwin's Date to the Bieber/Baldwin (wedding party)'," he tells the outlet.
"How much money could I raise for a kick a** charity? If I sold $20 raffle tickets, I could make $20 million!"
But he's thrilled Hailey, who is the daughter of his actor brother Stephen Baldwin, has found a great guy in Justin, revealing he has spent some quality time with the singer.
"I had a chance to have lunch with him recently... and it was nice to get a real hit of him," Billy says. "He's a very cool guy and super talented and he's got a huge heart - and they're madly in love."
The movie star didn't expect an invite to the wedding - if indeed the couple has already quietly exchanged vows - but he does implore Justin and Hailey to organise a proper party.
"You gotta take care of both families," he tells the news outlet.