PERSONALLY. I think their egg laying does not involve opening up for each other until they are ready to lay, due to the apparent horrific virus/bacteria/fungus/parasite/etc ridden air that they live in. I think most of the process is mentally driven or externally activated through sounds/vibrations. Not to say some don't have fun by opening up for each other to grab their lover's roe, but like. they would have to be really careful, really clean, or they would be doing it for the thrill and danger.
(remind me to make my Eridian clean room BDSM dungeon post)
anyway. all this to say that in my mind palace it is just one of those biological quirks that never evolved away bc there was no pressure. their insides have some nerves that can be seen if the ventral seam is open. Never an issue until space and light aliens.
BUT. what a fun idea!!! If I wasn't already committed to this in my fic I would be using it. Eridian Sex: You extend your flashing ovipositor towards your mates waiting hole/other ovipositor (whatever) and once their internal light pits recognize the light frequency of Eridian Genital Flashes (and not, hopefully, whatever parasite that probably exists that mimics this frequency) and this causes the pleasurable sensation of egg production/ descent/ what have you. No process until they can see the light!
and of course they have no idea this is what is happening. They have no fucking clue. They are having sex normal style with absolutely no idea part of their reproduction cycle depends on them having fiber optic lamp cocks.
And this means you can totally blind or overwhelm their light pits with enough wattage. How fun! Overstimulating that rock has never been easier and he has no idea why. Sex with the wet alien is just the best, for some reason. and the reason is the light drenched environment and it has nothing to do with the hands of mr. 'holy cow' himself.
