The best part for me is the woman is grinding, losing herself in the moment and really fucking my face. Her taste, scent, lube, all of it is everywhere and I can go from Pussy to Butthole and gyrate a rimming for her too. Sucking her Clit is easier in other positions so the focus when facesitting is just to get my tongue 2-3 inches up her and swirl it around. Combine that activity with her grinding and she gets to fuck not just be eaten out.