I've been in spaces where folks writing erotica have asked for a fifteenth synonym for "penis" and I cannot emphasize just how unnecessary it is to even need *one* if you're focusing on the actually important bits.
Which is RARELY the mechanics of what's happening.
Writing sex scenes is surprisingly fun, I thought I'd be getting caught up in conveying the action Wrong but choosing to focus on how the characters communicate and what they're feeling in the moment, like Talia said was the way to go, really does work