[DJ Sensei]

If he's drawing to a flush, he isn't folding to a smaller than pot sized bet, and you really don't want to make one of those and get called on a later street. After he checks behind on the turn, I'd make a blocking bet on the river. If he's drawing and missed, it'll take a lot more sack on his part to raise your bet, more likely he'll just fold. If you're beat, he'll call or raise. If you check the river, though, you're saying that you want no part in a showdown, and he can make a small bet like this with anything and chase you off.

Side note, I wouldn't raise AJo out of the blinds here, no matter how many limpers there are. You undoubtedly will get called, and playing AJo OOP postflop in a big pot suuuuucks, especially on flops like this.