Legally? No.
For a game? Nobody's going to give a fuck, not unless you directly copy-paste dev's game and call it something else. There hasn't been any large legal cases in relation to porn games using real images, afaik, but could have easily missed it.
Images or videos, unless stated clearly as CC0 or any other that falls under free commercial use, is never going to fall under fair use. It's copyrighted material and will likely stay that. I know that music loses its exclusive copyright and becomes public domain after 70 years or so, not sure about videos or movies, though. It's also worth noting that Patreon no longer accepts real-porn projects. Not sure if that means anything to you at all, just thought it was worth mentioning.