From my understanding as long as it is not pure digital adult goods, or anything delivered digital, it's okay. Some time back, they talked about even fining those selling adult goods, but yet there are all kinds of adult hardgoods on Ebay with Paypal being the processor. Adult Dvd's for one example. Guess they must have been talking about digital products, probably the big thing being subscriptions to adult paysites.
Why not ask them? Use a free e-mail, see what they say. Can't hurt.
Course you have some other way's you could be making money off your site, if you think about it..
Besides adult affiliate programs that is.
I know I asked a while back about digital adult e-books, they said no.