Pre-Flop Steal Turns into Big Pot

[W. Deranged]

2/5 No Limit Hold'em (Live)
7-handed


UTG, ("king" as he is called by some of the dealers) is a young, strong player who plays much too loose pre-flop but very well post-flop, is sitting behind by far the most chips at the table (~1500) and straddles to $10.

UTG+1 is a regular who has some skill but is too loose and is also on horrendous tilt. Calls the $10.

MP folds.

I'm one off the button with A4o. At this point, I have played almost no hands in the past hour. I'm new to the game but have played with many of the players in then and I'm pretty sure they all have me pegged as a tight (and to some that means bad...) player. I feel this is a good opportunity to pick up a small pot to stem the bleeding. I raise to $40.

The button is a very loose and impulsive player who has about $800 in chips. He calls too many hands on early streets but is capable of playing a marginal (or weak) hand strongly. He calls.

BB folds, straddler ("king") folds, Tilting calls, and three see the flop. ($137)

Flop: Ad Ah Qd, rainbow.

Tilting checks, I bet $60 (other amounts to consider??? this is clearly a small bet), Button calls, Tilting folds.

Turn: 6s

I check (???), Button bets $100, I call.

River: 5d

What's my play?

How do people like the line to this point and what's the plan for the river?