10NL: Two-pair versus calling stations on drawy board

http://weaktight.com/1167332

SB - 34/4/1.8 over 138 hands
MP - 34/6/0.8 over 86 hands

MP was a calling station.

I put both SB and MP on a flush or straight draw. Since the straight may have hit and the flush draw missed...is there any reason for me to bet? I am not value betting either way (since the busted FD would NOT be calling my bet).

$0.05/$0.1 No Limit Holdem
7 players
Converted at weaktight.com

Stacks:
UTG ($4.00)
UTG+1 ($12.70)
MP ($8.45)
CO ($10.00)
BTN ($3.40)
SB ($4.85)
Hero (BB) ($10.10)

Pre-flop: ($0.15, 7 players) Hero is BB :qc: :8d:
UTG calls $0.10, 1 fold, MP calls $0.10, 1 fold, BTN calls $0.10, SB calls $0.05, Hero checks

Flop: :8c: :3d: :4d: ($0.50, 5 players)
SB checks, Hero bets $0.40, 1 fold, MP calls $0.40, 1 fold, SB calls $0.40

Turn: :qh: ($1.70, 3 players)
SB checks, Hero bets $1.25, MP calls $1.25, SB calls $1.25

River: :7s: ($5.45, 3 players)
SB checks, Hero bets $4, MP calls $4, SB folds, SB says "nh"

[Results Hidden]

i probably play it the same

I believe that donk made a set on the river. Anyway, since he flat calls, the best hand he might have is a pair or weaker 2 pair. If he hit a set or straight he should have reraised somewhere, at least on the river. I would bet as much as I can with a heavily drawing board. nice play in long term against a calling station.