Here’s a bonus to marrying Debra Messing’s son: You might get your hands on her jewelry.

At Town & Country’s Jewelry Awards on Monday, Messing told us that her bauble box includes 5-carat diamond earrings from the 1880s that she bought from Fred Leighton.

But when we asked the “Will & Grace” star if she’d loan her jewelry to her son’s (theoretical) girlfriend, she said the woman would have to be an official part of the family first.

“If my son’s girlfriend ever wanted to wear my jewelry, I’d just say no. Even if it’s prom: No,” she told us at L’Avenue at Saks.

“If he’s marrying the girl, then that’s different. But let’s start with borrowing and then once the ring is on the finger and we know she’s family, of course I’ll be happy to give a few pieces away.”