Villain is unknown.

Poker Stars $0.50/$1.00 No Limit Hold'em - 7 players
The Official 2+2 Hand Converter Powered By DeucesCracked.com

BB: $102.00
UTG: $108.60
UTG+1: $100.00
MP: $72.95
CO: $122.40
BTN: $66.20
Hero (SB): $108.65

Pre Flop: Hero is SB with 5 5
2 folds, MP raises to $3, 2 folds, Hero calls $2.50 , 1 fold

Flop: ($7.00) 5 6 4 (2 players)
Hero bets $5, MP calls $5

Turn: ($17.00) Q (2 players)
Hero bets $15, MP calls $15

River: ($47.00) 7 (2 players)
Hero ???

He's got 50 left. Bet 30, call "shove". I can't see a reason to stop here.

I go $28 I wanna get alot of hero calls from crappy hands. Not foldng to a shove.

How is this a tough river spot?

At best he rivered 2 pair so just bet and call a shove.

ok glad b/c seems pretty standard. here's the gross results.

River: ($47.00) 7 (2 players)
Hero bets $18, MP raises to $49.95 all in, Hero calls $31.95

Because a lot of players are calling the flop and the turn with 33 and 77. I even lose this to 88 on occasion, but much less frequently (I can only recall two off the top of my head).

Seriously, I probably show down a loss in this situation to 33 and 77 around once every couple, three, thousand hands. Not at all uncommon.

But show it down. You need a player specific read to think about folding this. Go ahead and bet out for anything reasonable--77 is the best hand that usually calls--33, 88 and bluffs will raise and you'll get a fair number of calls by 2 pair hands and occasionally hands with a Q or a decent pocket pair.

He doesn't have enough behind to make me think about doing anything but bet/calling, though 4 straighted boards are never a good sign.