Alright, I don't bluff a lot considering it is NL50 but I just feel that he wasn't going to call anything if I bet enough on the river. I also do feel that he would have called an all in since it would have looked like an obvious bluff.
I really have no idea what my line is here, so comments please?
Poker Stars
No Limit Holdem Ring game
Blinds: $0.25/$0.50
6 players
Converter
Stack sizes:
UTG: $19.10
UTG+1: $49.25
CO: $96.85
Hero: $69.45
SB: $84.45
BB: $56.85
Pre-flop: (
6 players) Hero is Button with
3 folds,
Hero raises to $2, SB calls $1.75
(pot was $2.75), BB folds.
Flop:

(
$4.5, 2 players)
SB bets $2,
Hero raises to $6, SB calls $4
(pot was $12.5).
Turn: 
(
$16.5, 2 players)
SB checks,
Hero bets $10, SB calls $10
(pot was $26.5).
River: 
(
$36.5, 2 players)
SB checks,
Hero bets $25, SB folds.
Uncalled bets: $25 returned to Hero.
Results:
Final pot: $36.5