Were his chances of hitting a flush really that good though? That's the only thing that he could have been drawing to, assuming he wouldn't stay in with a 6s8s for $3 pre, and that's not good odds. If I appeared to have a weaker hand (like middle pair), I thought he'd be more likely to push hard on the turn, and when a lot of people push hard, it's really hard for them to let go. If that spade had dropped though, I would have been worried and possibly got out of the pot. But that's only going to happen something like what, 1 in 5 times...

Hmmm... definitely something to think about. I think you're right about re-raising him off the flop though, I'll probably play it like that from now on. I have been too passive in my playing in the past, I know this.