2 pair with three diamonds on flop.

[Rage2100]

Villain had been pretty aggressive but according to Sharkscope he was a fish. Is an all-in move the only option here with three diamonds on the flop and a possible straight draw? Can you ever be worried about an already made flush in this situation? His check-raise worried me as he had been coming out betting previously.
Also, should I have raised this pre-flop?

PokerStars Game #11203771517: Tournament #56835917, $5.00+$0.50 Hold'em No Limit - Level VI (100/200) - 2007/07/29 - 17:22:37 (ET)
Table '56835917 1' 9-max Seat #1 is the button
Seat 1: dirty_kauper (2670 in chips)
Seat 2: Villain (5770 in chips)
Seat 4: Hero (2555 in chips)
Seat 8: mr8083 (1100 in chips)
Seat 9: HEMIpowerSWT (1405 in chips)
Villain: posts small blind 100
Hero: posts big blind 200
*** HOLE CARDS ***
Dealt to Hero [2c As]
mr8083: folds
HEMIpowerSWT: folds
dirty_kauper: folds
Villain: calls 100
Hero: checks
*** FLOP *** [2d Td Ad]
Villain: checks
Hero: bets 300
Villain: raises 500 to 800
Hero??

[taipan168]

I wouldn't raise this preflop with your stack size and the two shorties around.

On the flop, once you hit your 2 pair, what you do is read-dependent. Has opp been using his big stack on the bubble to bully? If so, I would shove over his re-raise. Even if not, I probably don't give credit for a flopped flush, better two pair or a set - the chance of flopping a flush with two suited cards is like 0.8%. I think I'm shoving over here.

[Rage2100]

Thanks taipan, Villain was lucky to still be there to be honest and should have been out 3 or 4 times. He had a nice double up when he called a 4x BB (200 chips) UTG raise with his 88, the flop came down AK2, the raiser made a half pot sized c-bet and he went over the top and stuck his remaining 2000 chips in. The UTG raiser called with his AK and Villain hit his 8 on the river to stay in. He also had a few other similar lucky escapes.

In my 2 pair hand, I pushed over his raise and he called with Qd 3d, damn it, some people have all the luck!!