Big, shapely rear ends aren’t just for ladies.

Guys are getting into the bubble-butt game — and they’re buying the undergarments to prove it.

Brands like the Rounderbum — underwear that comes with polyurethane inserts sewn into the seat — are picking up traction with men, Vice reports.

These derrière-enhancing skivvies — backed by a “Shark Tank” mogul — are “the fourth best-selling pair of trunks” on Amazon, per Vice, and they’ve generated more than $1 million in sales since 2015.

What makes Rounderbum briefs so covetously bodacious? Look to the polyurethane cheeks. “When brands use silicone, it’s heavier and it’s a little more obvious if someone were to smack your butt,” inventor Jonathan Diersing tells Vice. “Ours is spongy, like a real butt.”

According to Rounderbum customer Brandon Gray, the undergarments actually work: “I’ve even had friends ask me if I’ve had cosmetic surgery.”

Diersing is not alone in selling goods that improve rear views for dudes. Karen E. Jones, the owner of booty-boosting brand Bubble Bodywear, tells Vice that sales to men are on the rise. “We had one doctor who felt self-conscious when residents were walking behind him,” she says, adding that he was plagued by sagging jeans. “He thought they were just staring at his flat butt.”