River check - 2 pair

Poker Stars
No Limit Holdem Ring game
Blinds: $0.10/$0.25
6 players
Converter

Pre-flop: (6 players) Hero is BB with 5 7
UTG folds, UTG+1 calls, CO folds, Button calls, SB calls, Hero checks.

Flop: 7 A 5 ($1, 4 players)
SB checks, Hero bets $0.75, UTG+1 calls, 2 folds.

Turn: 8 ($2.5, 2 players)
Hero bets $2, UTG+1 calls.

River: T ($6.5, 2 players)
Hero checks, UTG+1 bets $2.25, Hero calls.

Results:
Final pot: $11

How much does he have to bet for me to fold?

Do you be out here and fold to a raise instead?

I bet more on the flop and turn.

I dont mind a check/call on the river. I call anything pot sized or less.

c/c river is fine here. How big a bet I want to call really depends on my opponent, because there are so many hands out there that beat you. But this river call is pretty easy with those pot odds although it looks like a valuebet beating your twopair.