Heidi Klum Magic Helmet Head

12/27/2012 6:49 AM PST BY TMZ STAFF
Heidi Klum performed a supermodel magic trick Wednesday ... riding bitch with an extremely large helmet and then removing it ... only to reveal a perfectly coiffed head of hair.

Heidi was riding with her bodyguard-BF Martin Kristen in Venice, CA when she showed off her hat trick.
They've taken a serious step in their relationship, wearing similar get-ups, including hipster sunglasses.

Looks like they could Seal the deal.