Not much read on the opponent, he's got the table covered with about $245 (NL100).

I limp OTB with after several others. Opponent is BB and checks.

Pot size: $4.75

Flop:

It get's checked to me and I go ahead and bet $5 with my flush draw and gut shot draw. Opponent is the only caller.

Turn board:

Opponent checks to me again, I decide to keep pushing since he may fold and I've got outs. I bet $10 into the $15 pot. Opponent calls me again.

River board:

Great I've got a straight AND a flush, too bad that doesn't make straight flush (yes, I've seen people in live games announce this as a straight flush and it's always hillarious when the dealer has to explain it to them). Opponent checks again, now there are several possibilities, either he was slowplaying a set or something by checking and calling and he just got screwed, or he had a semi-weak hand for the action like maybe a QK or something, or he made the flush also and has some major balls by checking it to me.

I bet $15, here's where it gets interesting, he raises to $45. I go into deep thinking mode now, if he had raised to $30 I'd be putting him on the nut flush now but by the action, I don't think he can really put me on a flush too easily so this raise to $45 seems a lot more like KT or an attempt to push me off whatever I was betting by representing the flush. I considered flat calling but given all the possibilities I figured it was a lot more likely I had the best hand than not which eventually ended in me pushing all in for like $82 more. He instacalls and shows me , I've been thinking about this hand for like 2 hours now so I need some opinons who flat calls this river? Who plays the hand differently from the flop on? I guess I could have bet the full pot on the turn but I didn't give him odds regardless so that can't be that big of a mistake....I don't know.

I dont like the way he played this at all. He got very lucky that you also had a flush.
However, I also wouldnt have pushed in if I were you. Im about 90% sure I wouldve called because I cant believe he checked the nuts to you with that action.

I just dont see how he would possibly call your all in without the nut flush, so raising doesnt serve any purpose except to lose you more money when he has you beat.