What it says on the tin. Bruce having sex with himself. Partial to idiot playboy!Brucie getting banged by dark, intimidating Batman, but not necessary. Any kind of Bruce getting banged by another version of Bruce works; interdimensional shenanigans, magic, demon duplicates, weird wet dreams. Whatever floats your boat.

Bonus for branding (literally or with bites/hickeys) and sex up against the glass windows at the lakehouse. (Also, on mobile so sorry if there's any formatting issues.)