This is exactly what you should do. I've got quite a few friends in the swinger crowds, and if you're going to find a good, mature, financially responsible investor for a really good adult-oriented idea, your best bet is in the upscale swinger community.

I'll confirm that they're a mostly very open and very nice crowd, and there's a higher proportion of wealthy and intelligent people among them who would love to invest in a good adult-oriented startup - especially if it's a fresh idea.