Middle Pair concerns

[Nikademus]

So, one of the holes in my game is aggession. I think this is the type of situation where I tighten up because I'm not sure what to do.

SB - 13%/6% AF 2.14 after 285 hands - likely the best (solid) player at the table
UTG+1 - 17%/2% AF 1.14 after 89 hands - Tight-passive, but maybe not catching any real cards.
EP - 72%/1% AF 0.77 after 107 hands - Complete fish, will show anything down.


PokerRoom 1/2 Hold'em (10 handed) FTR converter on zerodivide.cx

Preflop: Hero is with K[img]/images/graemlins/diamond.gif[/img], J[img]/images/graemlins/club.gif[/img]. CO posts a blind of $1.
<font color="#666666">1 fold</font>, UTG+1 calls, EP calls, <font color="#666666">1 fold</font>, Hero calls, <font color="#666666">1 fold</font>, CO (poster) checks, <font color="#666666">1 fold</font>, SB completes, BB checks.

Flop: (6 SB) Q[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/spade.gif[/img], 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(6 players)</font>
SB checks, BB checks, UTG+1 checks, EP checks, <font color="#CC3333">Hero bets</font>, CO folds, SB calls, BB folds, UTG+1 calls, EP calls.

Turn: (5 BB) 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, UTG+1 checks, EP checks, <font color="#CC3333">Hero bets</font>, SB calls, UTG+1 calls, EP calls.

River: (9 BB) 7[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, UTG+1 checks, EP checks, Hero ...

I'm not sure what SB &amp; UTG+1 are hanging around for. From what I've seen, SB would have raised by now, and UTG+1 would have folded by now. EP doesn't worry me. So, I'm concerned about a Q, AJ, or a random 4. What's my line?

Thanks