An elaborate sexual maneuver; simply defecate into a air tight bag and place it over your partners head allowing minimal room for them to breathe, commence coitus from the rear, either hole is fine. Then in the last few seconds before climax remove the bag swiftly from your partners head leaving them gasping for air and likely tightening the vaginal / rectal cavities ensuring maximum enjoyment.
"I paid this prostitute an extra $50 last night to do the chocolate space man, I forgot the pull the bag off her head though and now I don't know where to bury her"
when someone has to fart and another person puts a bag around their head completely surronding it, then they cut a hole for the mouth to breathe. the participant opens their mouth and puts their face right next to his/her's ass and sucks in the fart as they blow it out resulting in the "spaceman".
When a women is on her head Naked vagina up and wide on her bed. you jump off your headboard like a Horny spaceman on a sex drive mission "Head first" Aka Penis First.