Ugly 2 pair

Both blinds were just calling stations but what's a standard line against decent opponents? Are we waiting for a non spade turn to get more frisky or are we chasing away As/Ks on the flop? Or fold the flop altogether?

PokerStars No-Limit Hold'em, $0.25 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

SB ($20.35)
BB ($13.70)
UTG ($33.45)
MP ($28.75)
CO ($31.35)
Hero ($43.25)

Preflop: Hero is Button with 9, 7.
UTG calls $0.25, 2 folds, Hero calls $0.25, SB completes, BB checks.

Flop: ($1) 7, 9, 2 (4 players)
SB checks, BB bets $1, UTG calls $1, Hero raises to $4, SB folds, BB calls $3, UTG calls $3.

Turn: ($13) 3 (3 players)
BB bets $5, UTG calls $5, Hero folds.

gnads,

I mostly raise this preflop, but a limp is okay if UTG and the blinds are huge calling stations postflop.
Flop is fine.
Turn I would raise to something like $15-18. check/fold river if a spade hits.