I don't see the significance of someone's irl gender in a roleplay, even if the roleplay is about sex or whatever. If someone's good at RP, then their character will act like whatever gender you desired anyway.

How about instead of

"I want to do 1x1 smexy times rp with female only."

It could be

"I want to do 1x1 smexy times rp with someone good at playing female characters."


At least, that's how I see it.