Why you shouldn't slow play the straight you just flopped

Definately worked out good for me though

POKERSTARS GAME #489181006: HOLD'EM NO LIMIT ($0.10/$0.25) - 2004/06/15 - 19:58:30 (ET)
Table 'Havnia' Seat #9 is the button
Seat 1: DagNasty ($9.80 in chips)
Seat 2: kaj. ($36 in chips)
Seat 3: BMcGinn ($29 in chips)
Seat 4: davfagan ($12.15 in chips)
Seat 5: JACKSINHOLE ($24.50 in chips)
Seat 6: Mac2 ($13.65 in chips)
Seat 7: richjeanna ($25.85 in chips)
Seat 8: Eoing ($11.10 in chips)
Seat 9: GJW3853 ($13.85 in chips)
DagNasty: posts small blind $0.10
kaj.: posts big blind $0.25
*** HOLE CARDS ***
Dealt to davfagan [As 7s]
BMcGinn: folds
davfagan: calls $0.25
JACKSINHOLE: folds
Mac2: calls $0.25
richjeanna: calls $0.25
Eoing: calls $0.25
GJW3853: folds
GJW3853 is sitting out
DagNasty: folds
kaj.: checks
*** FLOP *** [Qh 9s 8s]
kaj.: checks
davfagan: bets $0.50
Mac2: folds
richjeanna: calls $0.50
Eoing: folds
kaj.: folds
*** TURN *** [Qh 9s 8s] [Td]
davfagan: bets $0.75
richjeanna: calls $0.75
*** RIVER *** [Qh 9s 8s Td] [Ks]
davfagan: bets $2.50
richjeanna: calls $2.50
*** SHOW DOWN ***
davfagan: shows [As 7s] (a flush, Ace high)
richjeanna: mucks hand
davfagan collected $8.45 from pot
*** SUMMARY ***
Total pot $8.85 | Rake $0.40
Board [Qh 9s 8s Td Ks]
Seat 1: DagNasty (small blind) folded before Flop
Seat 2: kaj. (big blind) folded on the Flop
Seat 3: BMcGinn folded before Flop (didn't bet)
Seat 4: davfagan showed [As 7s] and won ($8.45) with a flush, Ace high
Seat 5: JACKSINHOLE folded before Flop (didn't bet)
Seat 6: Mac2 folded on the Flop
Seat 7: richjeanna mucked [Tc Jd] - a straight, Nine to King
Seat 8: Eoing folded on the Flop
Seat 9: GJW3853 (button) folded before Flop (didn't bet)