As others have said, try to get it all in on the turn. However, since you weren't able to, I like checking here. If he was on a flush draw, he's not going to call your bet. However, he might bluff at the pot, and you would make extra money by doing this. Also, in the event he has a made hand, he might decide it is best and bet it. I like checking here. It is an immediate call though, no need to even think about it. You're getting 4 to 1.