Um… I don’t know. I love rimming, but that’s about it.
According to urban dictionary, feltching means ‘‘Usually of a homosexual man: to stimulate the anus of (a sexual partner) orally; specifically to remove orally semen ejaculated into the anus of (a partner). Also: to insert a small animal, especially a gerbil, into the anus of (a partner) for sexual stimulation’’. In that case, NMK.