(To ooliyo, On, and Ponyboy) I don't think it's seemingly indecent at all (not even porn-like indecent). It's just a healthier version of the fat-laden, sugary sundae.
That doesn't sound like much of a sundae and how can it be a sundae if they didn't even use any icecream? I guess the saturdae enjoys getting devoured by others as well as himself.