Credit: Denise Truscello/WireImage

Heidi Montag -- who famously underwent 10 plastic surgery operations in one day -- stripped down to a bikini Saturday while hosting the Liquid Pool at Aria at CityCenter Las Vegas. (See more pics!)

Though she has told she wants bigger breasts, Montag, 23, told Jay Leno last month: "I legally can't right now. The limit is 800cc and I have 700cc."

She recently told Ryan Seacrest that, depending on the bra, her breasts are now size "E or F."

The only downfall: Montag said she is no longer able to jog.

Added The Hills star, "I'm very weird about hugging people now -- [my body] is very fragile."