https://www.youtube.com/watch?v=5eeJqrJ84Xs:750
Do you mean something like this?
I'm sure the Greeks did it for sure.
http://gaycomics.adultcase.com/files/2012/06/Gay-Comics-3D-11.jpg
in most cases if there's a will there's a way but picture yourself doing it.
What if the guy wants his legs up in the air. How many pillows?
reaching in (getting in) could take some logistics doing it. Besides most overweight guys are usually tight.