Interesting hand from 10-25 cash game

I have been playing a little bit of cash online and thought this was an interesting hand.

I question whether I should call three big bets in this case since the SB could easily have a 7. But after the fact, it is clear he played it even worse than I did. I mean, I could have easily had a 7 in the BB, and he probably should have slowed down a bit after firing the first two bets.

Tell me what you think.

Stacks:
UTG with $29.26
UTG+1 with $26.63
MP1 with $23.70
MP2 with $24.50
MP3 with $99.73
CO with $39.22
BTN with $25.00
SB with $41.55
BB with $50.01

Site: Full Tilt Poker
Dealt to BB:A♠ T♣

Preflop:
5 players fold.
CO raises to $0.75
BTN calls [$0.75]
SB calls [$0.65]
Hero calls [$0.50]
Total folds this street: 5
Potsize: $3

I hate my hand here. ATo is easily crushed. But I can't see any other way to play this properly than to call.

Flop:
A♦ 7♠ 7♥
SB bets [$3]
Hero calls [$3]
2 players folded.
Total folds this street: 2
Potsize: $9

A pot-sized bet into this flop does not smell like a 7 at all, so I call, planning to fold if the SB shows a lot of strength on the turn.

Turn:
10♦
SB bets [$9]
2 players fold.
Hero calls [$9]
Potsize: $27

This is either the worst card or the best card in the deck for me. If he's playing AQ or AJ, it's great. If he's playing 87, the T just got me deeper into a hand I pondered dumping.

River:
5♣
SB bets [$27]
Hero calls [$27]

This $27 bet only makes sense if he played a hand like 87 preflop. But it just doesn't add up. Still thinking that a guy who flopped trips would not have fired on the flop, I call this and pray.

Results:
SB shows :
A♣ K♦
Hero shows :
A♠ 10♣ Hero wins the pot ($78) with two pair, Aces and Tens