I love to see my character Liam dominated by naga, wrapped up in their tails, his ass being pumped full of eggs. I can't get enough of it, but all of my roleplays along these lines have not had a very romantic quality to them.
Liam is very prone to stockholm syndrome, so I would love to see a story where he ends up endebted to a naga, or kidnapped by one, and the two of them begin to fall in love. We could go with the eggs being fertile and Liam actually carrying children (a kidnapping prompt works best for this one, I think) or we could go with a story where the eggs are unfertilized and simply swell up inside his body and come out later.
In the second scenario, oviposition could be a very intimate and romantic thing, something they don't do until later on in their relationship.
I'm imagining the naga being masculine androgynous, where they appear as men to humans, but are in fact monosexual neither male or female, hence their ability to lay eggs.
PM me if you're interested :)