i did some research and found this quote from someone who wrote a comic on felching:
OK, since we didn’t get in any trouble with Snatch and Jiz, and a couple of these other comics, I was partying one night with Crumb, Wilson and these other guys. And Wilson mentioned to me, he says, "I was talking to Ken Weaver and he had this real interesting word." I said what, "What is it?" "A word called 'felch.'" I said, "What does that mean?" He said, "It is a real old term and it means orally withdrawing semen from someone’s lower digestive tract after having anal sex." I said, "There’s a word for something like that?" That’s incredible that not only is there a word like that, but it has a provenance. Hell yeah, we’re going to do a felch comic. So I talked to Crumb, "Yeah, we’re going to do a felch comic."that must be good reading! and think of the illustrations!