Responses
Mermen have a pouch where their Shlong Slider 3000 comes out of- I read a lot of fanfiction (I'm a goddamn degenerate) so the dirty is done either through there ORRR the mermaid/man has another orifice located somewhere on the body. If not- then its just the typical "lay egg, wait for mate to fertilize egg" situation.

man and here i thought I'll finally see mermaid porn sigh,,