This might be a stupid question, but is muffing exclusive to transfemmes or just especially common with them? (As in, do cis men have the potential to get the same pleasure from it?)
And is it possible to do on a perisex afab person? Or do they not have that canal??
Sorry, I don’t know how this works
Most people have inguinal canals, which is what you're stimulating with muffing.
The term was coined and the act was first written about by a trans woman (Mira Bellwater!), specifically in a zine about sex with/for trans women but it's perfectly possible for other people to do as well (though if you don't have a scrotum, it might be a little harder).
It's just not a commonly known type of sex. (If you're interested in learning more about it, this is a good article with instructions and resources!)
No apologies needed, hope this helps! <3