UTG ($6.65)
Hero (MP) ($2.53)
Button ($5.55)
SB ($0.89)
BB ($3.82)

Preflop: Hero is MP with 7s, 7d
UTG calls $0.02, Hero calls $0.02, 1 fold,SB raises to $0.10, BB calls $0.08, UTG calls $0.08, Hero calls $0.08

Flop: ($0.40) As, 10c, 9s (4 players)
SB checks, BB checks, UTG checks, Herochecks

Turn: ($0.40) Ac (4 players)
SB checks, BB checks, UTG checks, Herochecks

River: ($0.40) 7h (4 players)
SB bets $0.08, 1 fold, UTG raises to $4.28,Hero calls $2.43 (All-In), 1 fold

Total pot: $5.34 | Rake: $0.25

Everyone here are loose passive (including myself).

First, what made up a loose passive player?  He plays a very wide range of hand, and he does not get his money in unless he hit a big hand.  With UTG open limp and call a raise, I would like to put him on a mediocre hand, like small A, may be even suited, very small pair, or some mid low suited connector.

With the given actions, I really don't believe UTG had any A, unless he really like to extremely slow play his hand, which is very stupid in this level (2NL).  So, what made him shove on the river?  With his range, J-8, 8-6 made it, and it matches the style of a passive player, or if he had a busted 7-6/8-7, he really over played his hand.  Now, you need to ask yourself, How he played his draw before? Did he play that strong or weak?  How he played his split bottom pair? Did he lead out or he just check it all the way? I would personally put him on some kind of 7 that does not connect to the board, like a K-7.  

Now, for SB, he was either any 2 board way or pair of 8s

Whether it is +EV move for you, it all come down to the fact that, do you believe UTG made his straight for less than 46% of the time, since that that pot odd you had been offered(call $2.43 to will $2.91, 1.2 to 1).  Even if you may had the edge here, since it was so small, I would suggest you decided based on the fact that, whether you will go on tilt and kill the session if you happen to lose the hand instead of what his hole cards were.

a couple more, with UTG checked twice with the As, I don't think he had any board way pair neither, since he might be afraid of someone, especially SB had an A, while SB also checked the A two times up front, it UTG had any big pair, he should be confident enough to bet on the turn.

With such passive action in both previous streets, and showing sudden strength on the river, I would tends to believe he had the nut, instead of a stone cold bluff

Think I am posting my own analysis as well as the showdown soon...but seems no one's interested in this hand...lol

lets post your own analysis first, that's should be the most interest bit.... result is a minor thing

I went into think tank for 70 seconds and find the following:

Hands I'm winning

1. A weak ace w/o 7,9,T. He is the kind the player that overplays hands, so the preflop call sounds reasonable. Checks are also reasonable with this kind of play due to the fear of getting outkickered in by the guys in front. A5, A5, A6, A8, AJ fits into this category, 40 possible hands.

2. Strong ace AQ and AK. He would probably have bet it on flop, but there is still a minor possibility to it. Rounding down the 8 hands to half just to reduce the possibility. 4 possible hands.

3. Straight. 86 would be possible , J8 is highly unlikely due to preflop raise. 4 possible hands.

That makes me winning with 48 possible hands.

4. TT/99 I'd have bet these hands on the flop, but you really can't predict what happens in a cents table. 4 possible hands.

5. AT/A9. Slowplaying all the way and finding a prey finally on the trying to milk desperately, but the strong all-in move is best explained by these hands. 12 possible hands but I will adjust it to like 20.

6. A7/AA. Oh well. 2 possible hands. However these also explains the allin move perfectly, make it 4.

That leaves me with 28 losing hands.

The table has been quite passive and there isnt really any bluffs that get showed down in the hour I played, but there is always a possiblity to it, say 10%.

With the 28-48, or 1.6-1 plus the minor possibility of bluffing, although I inclined to the thoughts that he had the nuts, I called and found A7 in his hole, and the pot got shipped to him.

well well well... you just got unlucky and owned by his extreme passiveness.... with that 2nd A on the turn, he really should bet, since the chance of someone had another A that will out kick him and not betting on the flop is pretty slime....

I agree - you were unlucky here cos as played, your analysis made sense and it'd be extremely hard to lay it down (I know I would have to pay him off too). I would also have expected him to bet either the flop or turn to protect his hand from draws <-- lots of them! but again it's 2NL, so...

Now, away from your original question - just wondering, with hindsight, would you have played this hand differently? up til the river your 77 were pretty vulnerable. Free cards are great but you have no idea where you stand. OK if villain(s) showed strength you probably had to throw your hand away, but at this point, 4-handed, any A, T, 9 & JJ-KK (possible hand for SB) can beat you.

OK you hit the 7, but as you said, it still led to a bit of a tough decision. At this level, I would prefer to try to buy the pot or shut down by the turn, unless loose passive = they would call the turn with air or weak draw on this fairly scary board.

Thoughts?

No I'd have played it the same way. I was calling for set mining anyway.

My rationale behind the flop and turn is simply check-fold. This is a 4-handed pot and there is a high chance that I will be betting into a weak ace or mid pair that would chase me till river, with PFR and so much calls there is so much money in middle, the risk for me to take the pot right down there is really too high, I better keep the pot small. Taking free cards is actually MY strategy, them giving free cards to me is a grace.