Why not Bitpay? I'm not associated with them, and have never been on the merchant side of the transaction, but it seems like a 'safe' bitcoin option. And based on my quick read of their merchant TOS[0] bitpay shouldn't (in theory) have an issue with the nature of FetLife's business.
As an aside, it's fun to watch a bunch of old, technically-illiterate and conservative financiers unknowingly sow yet another little seed of their own destruction. I guess being at the top of the heap can make one feel invulnerable...