Not that it has ever happened to me but do you think it is weird to start having sex while they are sleeping and waking them up? Assuming they are a long time partner etc.
I had a GF that worked shifts and would have trouble sleeping. Sometimes she'd wake me up with a BJ if she was horny and wanted sex to wind down. downside was that she'd go to sleep afterwards and I'd be awake for hours. I didn't complain about it but no way would I do that to her or anyone else. That thing called consent... don't mess with it.