I usually dont get involved but how to play this: he showed afterwards

PokerStars No-Limit Hold'em, $0.25 BB (8 handed) from (Format: Bet The Pot)

MP1 ($32.15)
MP2 ($31.25)
CO ($22.70)
Button ($30.40)
Hero ($54.60)
BB ($27.05)
UTG ($10.60)
UTG+1 ($17.50)

Preflop: Hero is SB with , .
6 folds, Hero raises to $1, BB calls $0.75.

Flop: ($2) , , (2 players)
Hero bets $1.5, BB calls $1.50.

Turn: ($5) (2 players)
Hero checks, BB bets $3, Hero calls $3.

River: ($11) (2 players)
Hero checks, BB bets $8, Hero folds.

Final Pot: $19

why call the turn bet? you aren't getting the odds to call to hit your two outer, if you really don't beleive he has a J you have to call that river bet.

fold the turn

My feeling was he had to have something to call my flop bet, and thats either a J or the 3. On the other hand, he may not believe I have a J and could be calling with A high or even a different PP. I dont know, I rarely play any blinds vs blinds

On the river, I went against my feeling on the turn because of the size of the bet.

just fold.

Unusual play by him, he showed A5