Honestly? I would concentrate on the non-product side when first bringing it up. "There's this forum I hang out on with really cool people and they have contests and stuff..."
Just make it a natural point of conversation (probably best after
you've been intimate with each other to some degree). When you answer the follow-up questions you can slide something in there about the products we carry.
I personally prefer the direct approach but if you're unsure of how to proceed that's how I would do it. (If someone asked me, I'd just be like "yeah it's an adult toy site with cool social stuffs, what about it?")