raidencest guy here again. hehe. cyborg raiden and mgs2 raiden trying to do some sort of mission but cyborg raiden is just. ridiculously horny and at some point he has just GOT to try to impregnate that man (im a transfem/cis raiden truther so i dont know if he'd actually get pregnant but maybe the patriots invented mpreg. he has a hole he can get stuffed with cum its ok it counts)
Raidencest Guy, you're officially the only one left in my inbox to answer to! I can tell you had to repress yourself for long based on your horniness, NOT GOOD! Keep venting your horniness, boy, cum is better out than in (unless it's inside Raiden's ass, but that's for another story).
ANYHOW, of course in the MGS-universe mpreg is possible, I've said it a long time before about transmasc!Raiden having a bottom surgery that also makes him able to impregnate women (Rose), because it's basically a sci-fi, WHY WOULDN'T HE BE ABLE TO DO THAT!? Therefore, he can also get pregnant. For plot reasons, obviously. If not mpreg, cum inflation is a good compromize, especially to a baby-hater like myself <3
Snake catching Raiden having sex with himself is both funny but also, he looks so different in MGS4, I doubt Snake would recognize him or think "ahah, Raiden, you're fucking your future self".
IN CONCLUSION: don't worry about your fanfic!! Just post it or post it on Ao3 as an orphan work, even if my main suggestion will always be BE FREAKY ON YOUR MAIN!!!!!!!!!!! But you do you <3
Regardless, have fun writing your fanfic!
(My inbox is now empty, yeyyy!!!)