Michael Phelps‘ hot cocktail waitress GF has been around the block — in fact, she’s been around the WORLD … on private jets … long before she ever met Phelps … all because of her pretty face … and TMZ has the pics to prove it.

Sources tell TMZ, 25-year-old Megan Rossee ingratiated herself with the rich and famous through her job as a model at VIP events around the country — and thanks to her gig, she and her hot friends have been showered with lavish gifts by their elite admirers … including expensive trips to Vegas AND flights on private jets.

We’re told all the photos were taken within the last year — in the months before Megan and Phelps eventually came into contact.

And that’s why it pays to be hot.