Point during a massage session (i.e., asian massage parlour) just preceding the happy ending; whereas the client had spent the previous session time face-down on the table, "the flip" makes reference to one rolling on one's back, thus granting access of the "therapist" to one's family jewels.
"... Afterward she proceed's to give me a light massage which was alright but not her fault she can give a really good one you just have to say harder. Then came the flip and on to CBJ which quickly became a 69. Know I know I'm not the only one who would think this but this girl has got to have the tightest pussy I have every felt, I mean TIGHT!!!"