$2/$4 - TT vs Nit

Villain is 15/12 over 70 hands...thats all I know.

I never know what to do in these spots.
I always seem to give villain a shit load of credit and fold.

Do I call down here?

Poker Room skin
No Limit Holdem Ring game
Blinds: $2/$4
5 players
Converter

Stack sizes:
UTG: $485.00
CO: $983.20
Button: $259.20
SB: $461.70
Hero: $838.40

Pre-flop: (5 players) Hero is BB with T :diamond: T :club:
UTG raises to $15, 3 folds, Hero calls.

Flop: 4 :spade: 8 :diamond: 5 :heart: ($32, 2 players)
Hero checks, UTG bets $21, Hero calls.

Turn: 4 :heart: ($74, 2 players)
Hero checks, UTG bets $68, Hero

His bet seems a lot bigger on the turn in relation to the pot.
What, if anything, does that usually mean?

Against a nit and on this board I would fold the turn. Preflop call is fine against a UTG raiser with his stats but TT is usually a 3-bet for me.

call the turn, fold to a river bet.