If Marilyn Manson and Lady Gaga ever hooked up, this is what their kid might look like.

It's actually 17-year-old Gossip Girl star Taylor Momsen, Breaking Celebrity News has learned, and she's looking very... mature for her age in the get-up -- a racy mini-dress complete with garters, stockings, suspenders and lap dancer shoes.

The emerging star was seen Monday outside London's