rivered 2pair facing overbet FTP 25-50

[ceczar]

villian is arabiannight (i have him at roughly 18/12). we are playing on two tables currently, and have been for several hours. probably views me as willing to make thin/weak calls (though not necessarily on the river, i'm sure i'm bluffed out way too much on the river).

4 handed
villain (9,435) UTG
hero (6,242) B with K[img]/images/graemlins/heart.gif[/img] J[img]/images/graemlins/heart.gif[/img]

villain raises to 175, hero calls, blinds fold

flop (422): Q[img]/images/graemlins/heart.gif[/img] 3[img]/images/graemlins/club.gif[/img] 2[img]/images/graemlins/heart.gif[/img]
villain bets 350, hero calls
arabiannight is more than willing to repop with a Q or better here and i don't want to get blown off. he knows my range is pretty wide here (any pair or FD or OESD). mistake to call here even sometimes?

turn (1122): J[img]/images/graemlins/spade.gif[/img]
villain bets 850, hero calls
i think a call here is the only option, anyone disagree?

river (2822): K[img]/images/graemlins/diamond.gif[/img]
villain pushes, hero ?? (4,867 to call)

never seen him do this before, only thing i could think is a set hoping to get paid off by KQ/QJ here, but my hand is so underrepped. expecting most of you will say easy fold