No spoilers because this is just an opinion, but seriously: if you go to the Moon, wouldn't anyone want to try how 1/6g sex works?
Not when your bunk is a Navy surplus bunk and there is no physical way (short of climbing into the airlock) to be out of sight of your colleague.
And not if you want to have any chance of flying another mission.
Besides, all three of them are married, and while that might not stop Gordo, the other two seem a bit more serious about that. They’re not 20-some horndogs. They are mature professionals.
Also, to be completely frank...I really don’t see what difference the lesser gravity will make.
Even micro-G would be kind of irrelevant. If anything, the act would be harder when every thrust sends the two partners flying apart according to Newton’s laws of motion. If anyone IOTL has tried sex in space, they probably ragequit in frustration after the first two hours.