(vulgar) The act of sexual penetration or impassioned kissing or licking with the tongue
Verb
(vulgar) To sexually penetrate or impassionately kiss or lick with the tongue
1993, Nancy Friday, Women on top, page 81I begin to tongue-fuck his ear.
2000, Maxim Jubokowski, The Mammoth Book of Erotica, page 277"But then your tits are smaller than mine, so he might rather tonguefuck you other places."
2008, J.L. Langley, My Fair Captain, page 227Want me to tongue fuck you?