[Avgard]

There is not much to analyze here. The SB played the hand horribly. He should have check-raised you all-in after the flop.

The turn bet was fine to feel what he had. By calling both bets, it seems he had top pair (the fact that he had 2 pair and was a calling station shows his level of play).

The river bet can be debated two ways. If you pushed, he could have put you on a king in your hand making two pair kings over threes (beating his sevens over fours). So a push might have prompted a fold. By betting a similar amount as earlier, he probably thought you had a seven for sevens overs threes and he had sevens over fours. Your smaller bet probably got you paid off.

The other factor is your read on this player. You said he was playing less aggressive and turned into a calling station. If you sensed that he would have called the bet you made or an all in, then you should have pushed.