On last night's ``Tonight Show'' Fallon put his head between Heidi Klum's legs.

They were doing an acrobatic stunt, a head-to-heels roll forming a human wheel. They started with Fallon lying on a mat with Klum standing astride over his head. Fallon promised not to peek up her dress. Klum said the only thing to see up there was the transmitter to her wireless mic.

After they finished their roll, Klum told Fallon they were going to do it German-style. They did another series of rolls, this time belly-to-belly.