itch.io

Oh! Uhhhh… sure! I can provide some insight there! 

The first thing that comes to mind is any scene involving anal or oral and tentacles might have a chance to allow the tentacle to pass through, either for just an initial thrust, or for multiple. You could also add this optionally to Rinny's tail scene, since she hints at it a bit.

The other way you could do it is if the character is already cumflated, but comes across an enemy or event that that can anally or orally cumflate them again, there might be an add on to the scene where it “runs out of room” and it passes through. 

You could even add optional cumflation scenes to megacock scenes (like the teacher succubus, to name one off the top of my head), to add more chances for this to happen to the character.

Functionally, it just needs to be maybe a facial expression or two for anal scenes (face cheeks bulging or a surprised expression), and just showing whatever is making it through coming out on the other end. 

Otherwise, text and description carries it. It doesn’t have to be (and probably shouldn’t be) a very visceral description, and the most discomfort it should probably cause is an odd sensation of going through or some such, but obviously nothing violent or painful, as I get the sense that’s not the tone you’d prefer for this, and it would be much more palatable for you to write if it’s not a kink you’re interested in. Simply describing the feeling of being filled to capacity or the appendage going through as feeling weird as it travels through (very much without breaking anything of course) would likely be enough, so long as it’s done sensually.

I hope this gives a general idea, I wish I could help more, but I am no programmer, lmao. I do hope this helps, even if only in a small way. Sorry about the long comment, and if it was too much information. ^_^||