Why o Why?!?!?!?!

[tazmision89]

LIVE CASH GAME - NO LIMIT 5/10 - FULL RING (10 PLAYERS)

CHIP COUNT - $1,475

POSITION - SMALL BLIND

CARDS DEALT - Ad,Ks (BIG SLICK)

POSITION 1 - CALLS $10
POSITION 2 - CALLS $10
POSITION 3 - FOLDS
POSITION 4 - FOLDS
POSITION 5 - CALLS $10
POSITION 6 - FOLDS
POSITION 7 - FOLDS
POSITION 8 - FOLDS
POSITION 9 (ME) - RAISES TO $50
POSITION 10 (BB) - FOLDS

POSITION 1 - FOLDS
POSITION 2 - CALLS $40 MORE TO MAKE IT $50
POSITION 5 - CALLS $40 MORE TO MAKE IT $50

POT - $170

FLOP SHOWS - 6s,Kc,9s

POSITION 9 (ME) - CHECKS
I check to get a feel of who has what
POSITION 2 - CHECKS
POSITION 5 - BETS $50
Put him on TP/MP based on the small bet

POSITION 9 (ME) - CALLS $50
I could have raised here but I was confident I was in strong position
POSITION 2 - CALLS $50 (LIMPS)
At this point I put him on the straight/flush draw

POT - $320

TURN SHOWS - 2d

POSITION 9 (ME) - BETS 2.5x's THE POT ($800)
POSITION 2 - CALLS (ALL-IN $675)
Yeah!!....Huh??.....Wait.....What????.....
POSITION 5 - FOLDS

POSITION 9 - TPTK
POSITION 2 - 7s,8s (STRAIGHT / FLUSH DRAW!!!!!!!)


POT - $1,670

RIVER SHOWS - 5s

POSITION 2 WINS $1,670 WITH STRAIGHT FLUSH 5 TO 9

Now my question here is, what in the hell was this guys thinking calls a 2.5 pot size bet on just a draw???????? I could have easily betted on the flop with a pot size bet and scared everyone away, but I wanted to see what everyone was on. Maybe my curiousity got the best of me, but no REAL poker player would have ever made a crazy call like that. Especially for all your chips on a draw!!!!

I have the worst 2 weeks. I am playing really good poker but I just keep running in to people like this.

Crazy!!!!