25nl KK Donked turn, checked river

[vixticator]

Opponent is lag through 40ish hands, like 42/18/12. I don't believe him on turn IMO he raises flop with a Jack most of the time. Maybe draw, an eight, small pair, two broadway, anything really. Checks river so I basically rule out every hand that beats me.

Should I ever shove this or just bet a normal value amount, or even less since I think he's posturing on the pot to induce a bluff? Like, $5, which also gets an eight to call? Hmm.

Poker Stars, $0.10/$0.25 NL Hold'em Cash Game, 5 Players
LegoPoker Hand History Converter

CO: $5
Hero (BTN): $28.15
SB: $25.40
BB: $25.15
UTG: $47.35

Pre-Flop: K[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/spade.gif[/img] dealt to Hero (BTN)
UTG calls $0.25, CO folds, <font color="red">Hero raises to $1.25</font>, 2 folds, UTG calls $1

Flop: ($2.85) 4[img]/images/graemlins/heart.gif[/img] J[img]/images/graemlins/club.gif[/img] 8[img]/images/graemlins/diamond.gif[/img] (2 Players)
UTG checks, <font color="red">Hero bets $2.50</font>, UTG calls $2.50

Turn: ($7.85) J[img]/images/graemlins/diamond.gif[/img] (2 Players)
<font color="red">UTG bets $5.25</font>, Hero calls $5.25

River: ($18.35) 5[img]/images/graemlins/club.gif[/img] (2 Players)
UTG checks, <font color="red">Hero bets $19.15 and is All-In</font>