Whats the best way to protect your 2 pair postflop & prevent a suckout

[HardGrind]

I realize that i allowed my opponent to suck out on me by not going all in post flop. In all honesty, being that the flop was rainbow I knew I had the lead. In previous hands the table was playing a lil aggressive so thought it was best to play passive. I really didnt think that player6 caught the board at all based upon his previous play(very loose). So when he made the $2 bet I thought he was just trying to push us out.

How could I have detected this before the missile exploded? Thanks.



Full Tilt Poker - Pot Limit Hold'em Cash Game - $0.05/$0.10 Blinds - 8 Players - (LegoPoker Hand History Converter)

SB: $8.55
BB: $12.75
UTG: $8.05
Hero (UTG+1): $1.85
MP1: $10.00
MP2: $2.30
CO: $8.30
BTN: $2.80

MP1 posts $0.10
Preflop: Hero is dealt 4[img]/images/graemlins/spade.gif[/img] Q[img]/images/graemlins/spade.gif[/img] (8 Players)
UTG calls $0.10, Hero calls $0.10, MP1 checks, 3 folds, SB calls $0.05, BB checks

Flop: ($0.50) 4[img]/images/graemlins/heart.gif[/img] 7[img]/images/graemlins/spade.gif[/img] Q[img]/images/graemlins/club.gif[/img] (5 Players)
SB checks, <font color="red">BB bets $0.25</font>, UTG folds, Hero calls $0.25, <font color="red">MP1 raises to $0.50</font>, SB folds, BB calls $0.25, Hero calls $0.25

Turn: ($2) 4[img]/images/graemlins/heart.gif[/img] 7[img]/images/graemlins/spade.gif[/img] Q[img]/images/graemlins/club.gif[/img] 7[img]/images/graemlins/heart.gif[/img] (3 Players)
BB checks, Hero checks, <font color="red">MP1 bets $2.00</font>, BB calls $2.00, Hero calls all-in for $1.25

River: ($7.25) 4[img]/images/graemlins/heart.gif[/img] 7[img]/images/graemlins/spade.gif[/img] Q[img]/images/graemlins/club.gif[/img] 7[img]/images/graemlins/heart.gif[/img] 9[img]/images/graemlins/spade.gif[/img] (3 Players - 1 All-In)
<font color="red">BB bets $7.25</font>, MP1 folds
Uncalled bet of $7.25 returned to BB

Pot Size: $7.25 ($0.70 Rake)

BB had K[img]/images/graemlins/spade.gif[/img] 7[img]/images/graemlins/club.gif[/img] (three of a kind, Sevens) and LOST (-$2.60)
Hero had 4[img]/images/graemlins/spade.gif[/img] Q[img]/images/graemlins/spade.gif[/img] (two pair, Queens and Sevens) and LOST (-$1.85)