It's a slippery slope ... the beginning of a problem ... with the possibility of warns and bans forthcoming.
The question personalizes the discussion ... for one's gender, race, or ethnicity will rarely, if ever, be the topic.
Having said that, such questions have been asked and answered with no problem, but it's shaky ground.
Oftentimes folk share this information willingly, but no one is required to disclose such, even if asked.
We're a community, folk hanging out, such questions might be asked without consequence ... no violation.
It depends on how it turns out i guess ... what kind of disruption it causes ... what the intent looks like to me.
If you're willing to accept all that may come as a result of asking such ... personalizing the discussion ... feel free.
If you have more questions just ask.
Destee