Damned if you do and damned if you don't... :)
I can understand where you're coming from, OP. I have friends who are married or in a LTR (happily or unhappily) and the single ones who are in a similar boat to mine, single and looking...
Some the married/LTR sort are quick to judge you as being slutty if you do have sex on the first date... which is why I don't discuss my sex life with them, although I do politely tell them my opinion, which is "do whatever floats your boat" and "it's none of your business".
Having said that, even though I rationally think there is NOTHING wrong with sleeping with someone on the 1st date, I do feel a bit of guilt when doing it, especially when I don't have any plan on seeing them again. I was raised/programmed by my family/society to think like that, and no matter how much times have changed and all that, I do feel it. Nothing a couple of glasses of wine and talks with similar minded friends won't fix, though... Looking back, I don't regret anything I ever did, because it does align with my beliefs (despite the perceived societal norms pressure).
Whatever you choose to do, it is really no one's business and there is no right or wrong on this one... so perhaps stop sharing you life details with others - if you think it antagonises some your friends or if you feel judged by them?