Sex in space would be interesting, I think. Kissing and touching would be fine as you floated weightless around the room, which hopefully only had round corners and no sharp objects. The gentle spinning around and around would be pleasurable.
But can you imagine trying to fuck? Without gravity, you’d have to thrust as you pushed off of a wall, and it would be deep penetration. I could squeeze myself around your cock, but we’d have to strap on gravity boots – or at least one of us would, to get the motions right. I think it could be fun in a weightless environment, although it could get messy.
And it certainly would be quieter than normal, because in space no one would hear me scream.