Ultimate GFE (Girl Friend Experience)--when a prostitute behaves like her client's girlfriend in bed. A "regular" GFE experience will necessarily include kissing (both Light French and Deep French kissing), cuddling, and a generally unrushed experience. Ultimate GFE adds to this full and complete bareback sex (both oral and vaginal), much as one would do with one's girlfriend. An Ultimate GFE, in bed, is therefore completely indistinguishable from being with one's girlfriend.
"Dude, that chick I picked up on TER gave me an ultimate GFE experience...even got to cream inside of her."