Last night I was at a bar where most people are out-of-towners (beach community), started dancing with an older target, passed age shit-test, built attraction, k-closed, liked my odds for f-close, so asked for # to facilitate, she avoided, I thought id continue without it, continued dance/k-close, tried to escalate and she revealed she was married, producing a ring that she hadn't been wearing earlier in the night. There was a marked chilling of attitude at that point so I immediately moved on. In hindsight, I believe avoiding giving a # should have been a huge red flag. I am tempted to consider such a move a deal breaker in the future. Which leads me to my question: what are your biggest / most-encountered red flags?

Tl:dr what are your biggest / most-encountered red flags?