Hand right after the J9s hand, no reads.

Party Poker
No Limit Holdem Ring game
Blinds: $0.50/$1
6 players


Stack sizes:
Hero: $100.00
UTG+1: $53.73
CO: $67.92
Button: $297.20
SB: $413.90
BB: $109.01

Pre-flop: (6 players) Hero is UTG with
Hero raises to $4, UTG+1 folds, CO calls, 3 folds.

Flop: ($9.5, 2 players)
Hero bets $8, CO raises to $21, Hero?

I played an almost identical hand yesterday but did it differently. Opponent had a full stack and I was the one with half a stack.

I had JJ, flop came 45T with a flush draw. I bet pot, he miniraised me and I just flat called and then pushed the turn (slightly more than pot). He had T7 and sucked out. I was planning to push any non flush turn that wasn't a T, since I figured him either for TP or a flush draw.

I'm not sure which option is best.