Why cant i leave heads-up Omaha alone

it always kills me, look at this fucking hand he calls all the way with an open end straight draw pot bets

Full Tilt Poker Game #20916120854: Table Chamber (heads up) - $0.25/$0.50 - Pot Limit Omaha Hi - 16:12:02 ET - 2010/05/17
Seat 1: fatmorpheous ($63.70)
Seat 2: islaughteryou ($38.60)
islaughteryou posts the small blind of $0.25
fatmorpheous posts the big blind of $0.50
The button is in seat #2
*** HOLE CARDS ***
Dealt to fatmorpheous [Ad 4s As Jc]
islaughteryou raises to $1.50
fatmorpheous raises to $4.50
islaughteryou calls $3
*** FLOP *** [2h 9h 3s]
fatmorpheous bets $9
islaughteryou calls $9
*** TURN *** [2h 9h 3s] [Qs]
fatmorpheous bets $27
islaughteryou calls $25.10, and is all in
fatmorpheous shows [Ad 4s As Jc]
islaughteryou shows [4c Kc 5c Qc]
Uncalled bet of $1.90 returned to fatmorpheous
*** RIVER *** [2h 9h 3s Qs] [6c]
fatmorpheous shows a pair of Aces
islaughteryou shows a straight, Six high
islaughteryou wins the pot ($76.70) with a straight, Six high
*** SUMMARY ***
Total pot $77.20 | Rake $0.50
Board: [2h 9h 3s Qs 6c]
Seat 1: fatmorpheous (big blind) showed [Ad 4s As Jc] and lost with a pair of Aces
Seat 2: islaughteryou (small blind) showed [4c Kc 5c Qc] and won ($76.70) with a straight, Six high

FFS i had two of his aces as outs and a 6 of spades gives me a flush

down to bankroll $700 as tilted a bit, getting no-where fast.