Time for another 'swimsuit' topic!

So I was invited to go swimming, but I need a swimsuit. My question is actually about using dressing rooms in the store. Are there any rules on trying on swimsuits in terms of hygiene? I couldn't find anything about that on these forums or even Google. I would assume it's an issue that affects cisgendered women in addition to transwomen. It seems to me like less of an issue with traditionally male swimwear because it tends to be baggy enough to try on with underwear beneath.

Typically, you would wear underwear underneath. Obviously, you don't want to go in wearing extra thick granny panties, else they would alter the fit. Wear something dainty and small. They also generally have a sanitary liner in them.

I've always tried (female) swimsuits on with underwear underneath in dressing rooms, just as common courtesy (depending on the store, sometimes it's an actual rule and other times it's an implied courtesy-- at least, that's the impression I got). It's never caused me any issues in being able to determine whether the swimsuit fit or not. If you can't fit a swimsuit on while wearing undies, the swimsuit is probably too small anyways, so you should be fine~

Yes underwear underneath when trying them on. I saw a sign at Macy's that said that as well the other day.

Until surgery, I'll wear underwear underneath my swimsuit anyways so that works hehe.

My sister's store (a Primark branch) doesn't allow trying on undergarments or swimwear, and has a strict no-returns policy regarding them once worn.

Most def should wear underwear while trying on swim suits, as a courtesy and to protect ourselves
from cooties, whatever they are.