nut flush on a paired board

[private joker]

Consider this the opposite of the hand Heisenb3rg just posted.

Reads:
EP - bad, a little too loose, a little too passive, not at all creative
button = 2+2er Aragorn, tight and aggressive
BB - stupid

I miss the blinds and post 6 chips in the cutoff. EP raises, I call with Q[img]/images/graemlins/diamond.gif[/img]8[img]/images/graemlins/diamond.gif[/img], Aragorn cold-calls on the button, BB calls. (The SB might have called too, but if he did he folded on the flop so ignore it).

Flop comes A[img]/images/graemlins/diamond.gif[/img]3[img]/images/graemlins/club.gif[/img]3[img]/images/graemlins/diamond.gif[/img]. Checked to EP who bets, I call, Aragorn calls, BB calls.

Turn is 4[img]/images/graemlins/spade.gif[/img]. BB checks, EP bets, I call, Aragorn calls, BB calls.

River is K[img]/images/graemlins/diamond.gif[/img]. BB checks, EP checks, I bet, Aragorn raises, BB folds, EP cold-calls...

Who calls and who 3-bets, and why?