Credit: Jeff Kravitz/FilmMagic

She's made out with Madonna -- but no Gaga for Britney Spears!

At Sunday's MTV Video Music Awards in L.A., Britney Spears accepted a Michael Jackson Video Vanguard Award from another pop queen: Lady Gaga, in full drag as Jo Calderone, her male alter-ego.

And though Spears, 29, and Gaga, 25, shared an initial chaste smooch, the "I Wanna Go" singer awkwardly (but cheerfully) avoided Gaga's advances for a more intense makeout session. (Spears and Madonna, now 52, famously swapped spit during an unforgettable 2003 VMAs performance.)

"It was interesting, her character," Spears told MTV News backstage. "We got onstage and we felt it out."

Gaga (as Calderone) accepted the rejection with poise. "I don't want Gaga to get pissed."

Backstage, Gaga (still in character) effused about Spears. "She is f***ing hot. She is  f***ing Britney Spears.  Didn't you j*** off to Britney when you were a kid?