25NL : Crying river call ?

Villian Stats : (VP$IP/PFR [Street Aggression] 3-bet%)

BTN: 53/0 [4 1 1] 0% over 52

My Thoughts And Questions

Preflop and flop std for me.

On turn i feel there is still enough weakly made hands and draws out there i can still bet for value.

Now river for me is definitaly to check and see what villian does. Villian does seem quite passive......i am getting like 4 to 1...... there is a busted flush draw out there.... meh

Poker Stars $0.10/$0.25 No Limit Hold'em - 5 players

BB: $26.20
Hero (UTG): $25.50
CO: $25.00
BTN: $15.95
SB: $50.35

Pre Flop: ($0.35) Hero is UTG with Q K
Hero raises to $0.75, 1 fold, BTN calls $0.75, 2 folds

Flop: ($1.85) K 6 T (2 players)
Hero bets $1.50, BTN calls $1.50

Turn: ($4.85) J (2 players)
Hero bets $3, BTN calls $3

River: ($10.85) 7 (2 players)
Hero checks, BTN bets $3.50, Hero?

I call
it's funny, you think "he's not stupid enough to use that bet sizing as a bluff, there is no way" but you see that SO much

or even like he's confused whether he's bluffing or valuebetting and bets like a ten for that exact amount

There is no way I fold here