Apollo 12, which landed in November 1969, is rumored to be “The real 69 moon landing” (as opposed to Apollo 11, which landed in July 1969). Alan Bean, the first person to hit a golf ball on the moon, apparently tried to rack up some other “firsts” during his three days on the lunar surface with Pete Conrad. A law firm in Texas reportedly has a statement from Bean that they are to release 20 years after his death, which was in 2018.
I just made all that up, but anything is possible.
This may be difficult to resolve without commercial moon visits.
A married couple has been to space non-commercially before - and yet, I only vaguely remember some innuendo that may or may not have been first-hand about potential freakiness.
Our culture is incredibly (unreasonably, imo) prudish about discussing how pervy we are "behind closed doors" (or behind closed airlocks.)
The couple, who met during training, were assigned to the STS-47 mission in 1989. Lee and Davis were married in January 1991, but didn’t tell NASA until after the ceremony. Though a NASA spokesperson noted that “there was an unwritten policy not to put husbands and wives on the same flight,” there wasn’t enough time to train new astronauts for the Endeavor’s mission. So, the couple got to takeoff together (and NASA made their unwritten rule a formal policy).
Further, astronauts are career-oriented professionals. You don't get to be a career-oriented professional if you flaunt any actual written rules. Sometimes you can flaunt an unwritten rule if it seems cute and innocent. I don't think "don't fuck in space" is currently a written rule - but I also wouldn't be surprised if NASA made it an official policy before there was another obvious opportunity.
The ISS is co-ed. We haven't heard any reports of people fucking. Have people has sex on the ISS? I'm not very sure. Maybe 60%? I'd certainly try if I was up there and someone was flirting with me and we had some alone time - but I'm also super-duper not astronaut material, even if I had the talent of a military test pilot and super-engineer.
For the moon? Well, even if this whole Artemis nonsense actually works out (not terribly likely, imo) - I kinda suspect there won't be an opportunity for anyone, NASA will work to make it not have a chance to happen, and the people involved won't be at all likely to mention it even if they do pass some time seeing how cumming works in low-gravity.
If there's a year-round crewed moon-base at some point? Maybe the fucking happens, but do we hear about it? Seems unlikely - unless we're talking like >2050 on the timeline and culture has changed and NASA can't find any astronauts who've never been exposed or exposed themselves as fuck-happy degens.
I don't think this is actually important to resolution criteria, unless you wanna talk about how you'd handle resolving the market in the case where people who go to the moon make innuendos about moon-sex (like if someone answers a news reporter saying: [😉😏] "what happens on the moon stays on the moon!")
But considering the specifics of missions being planned (check out Smarter Every Day's very polite skewering and roasting of the Artemis mission plans,) and considering the culture around Very Serious People rarely ever explicitly admitting that they even have working genitalia - those feel important to the probability estimates people are making of this.