NL 100: two pair facing overbet on river in small pot

[Robert]

Opp is very loose, so I assume he's bad, but I got nothing else on him. Easy river fold?

Party Poker No-Limit Hold'em, $ Hero (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

SB ($75.25)
Hero ($109.75)
UTG ($131.80)
MP ($19.30)
CO ($74.52)
Button ($92)

Preflop: Hero is BB with 7, Q. SB posts a blind of $0.50.
4 folds, SB (poster) completes, Hero checks.

Flop: ($2) 3, 8, 7 (2 players)
SB checks, Hero bets $1.5, SB calls $1.50.

Turn: ($5) 6 (2 players)
SB checks, Hero checks.

River: ($5) Q (2 players)
SB bets $15, Hero calls $15.

Final Pot: $35

[andy-akb]

Ugh, I hate hands like this. Had our opponent lead into us, I would be raising this river nearly every time but against a big bet I am going to just call, I really dont like folding here without reads. I have no idea what to put him on, but I think we are going to see total air here enough to make this profitable.

Again though this is a spot I hate, any other insight would be greatly appreciated by me as well.