Fold KK HU to reasonable opponent

[Borno]

10/20 Live 11 handed

I've been in 4 orbits and have played like 4 hands or something, previous had I got my aces cracked against an awful player on a double paired board. I've got a TAG image.

Villian makes loose calls pf but hasn't raised pf and doesn't go out of line post flop (folds quite a bit on the flop). He looks like he's up about a rack.

1 call (from loose donk), villian raises in MP3, Hero 3 bets in CO all fold, Donk calls, villian calls.

Flop: Ad Jd 4c POT: 10.5SB

Donk checks, Villian Checks, Hero bets, Donk folds, Villian calls

Turn: Ad Jd 4c 2c POT: 6.25 BB

Villian hesitates for half 3 seconds and bets. Hero thinks for 15 seconds and calls planning to call down.

River: Ad Jd 4c 2c Js Pot: 8.25 BB

Villian bets, Hero thinks and folds.

With his raise pf and the J on the river I figure I'm ahead of almost no hands unless he was semi-bluffing a 15 outter. The pot isn't huge so folding isn't terrible imo. Thoughts?