Is my flop bet sizing okay? I figured we didn't have enough behind and that since the pot was big enough already, he wasn't getting correct odds

PokerStars No-Limit Hold'em, $0.10 BB (8 handed) - Poker-Stars Converter Tool from FlopTurnRiver.com

saw flop

CO ($9.70)
Button ($9.05)
SB ($5.10)
Hero (BB) ($37.40)
UTG ($1.85)
UTG+1 ($10.35)
MP1 ($7.90)
MP2 ($8.45)

Preflop: Hero is BB with K, K
1 fold, UTG+1 calls $0.10, MP1 calls $0.10, MP2 calls $0.10, 2 folds, SB calls $0.05, Hero raises to $0.70, UTG+1 calls $0.60, 1 fold, MP2 calls $0.60, SB calls $0.60

Flop: ($2.90) 3, K, 8 (4 players)
SB checks, Hero bets $2, UTG+1 calls $2, 2 folds

Turn: ($6.90) 2 (2 players)
Hero bets $4, UTG+1 raises to $7.65 (All-In), Hero calls $3.65

River: ($22.20) Q (2 players, 1 all-in)

Total pot: $22.20 | Rake: $1.05