These are three KK hands from yesterday.

Hand 1: Button was 42/7 over 69 hands. Do I just check the river or bet again? Checking seems to say I don't have the Q, but I'm not sure what he's been calling with, so he may pay off a smallish bet with a worse hand. If he has a decent hand without a Q, he may check behind.
Hand 2: UTG+1 was 85/24 over 34 hands. Is this a check/fold on the river?
Hand 3: Button was 52/8 over 48 hands. SB was 64/11 over 53 hands. For about the last ten hands, these two had been abusing each other in the chat window, and playing almost every pot together. I was pretty sure all their chips were going in the pot, given the action so far. Is folding on the flop too tight?


-----Hand 1-----
Hold'em No Limit ($0.05/$0.10)

Hero: ($15.33)
UTG+1: ($18.48)
CO: ($7.40)
Button: ($14.83)
SB: ($6.48)
BB: ($8.85)

Preflop: Hero is UTG with K , K .
Hero raises to $0.40, 1 fold, CO calls $0.40, Button calls $0.40, SB calls $0.35, 1 fold

Flop: ($1.70) T , 4 , K (4 players)
SB checks, Hero bets $1.40, 1 fold, Button calls $1.40, 1 fold

Turn: ($4.50) J (2 players)
Hero bets $3, Button calls $3

River: ($10.50) 9 (2 players)
Hero ??


-----Hand 2-----
Hold'em No Limit ($0.05/$0.10)

Hero: ($22.90)
UTG+1: ($11.06)
CO: ($4.33)
Button: ($11.57)
SB: ($11.90)
BB: ($13.73)

Preflop: Hero is UTG with K , K .
Hero raises to $0.40, UTG+1 calls $0.40, 4 folds

Flop: ($0.95) 2 , 3 , 4 (2 players)
Hero bets $0.70, UTG+1 calls $0.70

Turn: ($2.35) T (2 players)
Hero bets $1.70, UTG+1 calls $1.70

River: ($5.75) 5 (2 players)
Hero ??


-----Hand 3-----
Hold'em No Limit ($0.05/$0.10)

UTG: ($31.96)
Button: ($20.11)
SB: ($8.65)
Hero: ($25.16)

Preflop: Hero is BB with K , K .
1 fold, Button calls $0.10, SB calls $0.05, Hero raises to $0.50, Button calls $0.40, SB calls $0.40

Flop: ($1.50) 5 , 9 , 8 (3 players)
SB checks, Hero bets $1.20, Button raises to $2.40, SB calls $2.40, Hero ??