Should I have slow played this flopped top 2pr?

$5 + $0.50 Sit & Go (1014287), Table 1 - 20/40 - No Limit Hold'em - 0:13:26 ET - 2005/07/23
Seat 1: The Degenerate (1,350)
Seat 2: Joe DAgostino (1,495)
Seat 3: bwconvention (1,635)
Seat 4: bendejo106 (2,280)
Seat 5: wikkiwikki (1,515)
Seat 6: soulsurfer (2,255)
Seat 8: dj9033 (1,980)
Seat 9: The Rube (990)
Joe DAgostino posts the small blind of 20
bwconvention posts the big blind of 40
The button is in seat #1
*** HOLE CARDS ***
Dealt to bwconvention [Td Js]
bendejo106 folds
wikkiwikki folds
soulsurfer folds
dj9033 calls 40
The Rube folds
The Degenerate folds
Joe DAgostino calls 20
bwconvention checks
*** FLOP *** [Tc Jd 5d]
Joe DAgostino checks
bwconvention checks
dj9033 bets 40
Joe DAgostino calls 40
bwconvention calls 40
*** TURN *** [Tc Jd 5d] [6s]
Joe DAgostino checks
bwconvention checks
dj9033 bets 80
Joe DAgostino calls 80
bwconvention calls 80
*** RIVER *** [Tc Jd 5d 6s] [9s]
Joe DAgostino checks
bwconvention bets 480
dj9033 calls 480
Joe DAgostino raises to 960
bwconvention raises to 1,475, and is all in
dj9033 folds
Joe DAgostino calls 375, and is all in
Uncalled bet of 140 returned to bwconvention
*** SHOW DOWN ***
bwconvention shows [Td Js] (two pair, Jacks and Tens)
Joe DAgostino shows [Ks Qs] (a straight, King high)
Joe DAgostino wins the pot (3,630) with a straight, King high
*** SUMMARY ***

I "let" him hit his straight. What would you have done instead?