Strange play

[Keepitsimple]

I raise on the button with high cards, bb 3-bets, I call. Flop comes low with a flush draw. BB checks, I get confused and check behind with my high cards. Turn another low card. BB checks, I bet, bb raises.

Now this has happened 3 times the last 500 hands by different people. Is this a new line for flush draws or something? I have folded every time.

FWIW, Its 10/20.