Heads up hand question.

[TheJunkyardGod]

My friend and I were bored last night and decided to imitate the Greenstien/Negraneu battle and play heads up. There wasnt too many big collisions but on this hand I wanted to get some people opinions.

We each started with 100 dollars in chips and the blinds were 1/2. My friend plays very agressively and tends to like bluffing. We had been switching games up and he gained a decent lead while playing stud. The game switched over to NL hold'em and played this hand.

I was in the sb with 4c4s I raised it to 3 and he called the 2 dollars.

The flop came Qc 8d 5h

He checked and I bet out 5 dollars, again he called. He had a tendency to check raise when he made top or middle pair so since he called I really couldnt figure this out.

turn was the 9 of spades. Again he checked, and I counted out 20 bucks in chips and pushed them into the pot. After about 3-4 minutes of thought, again he called. It was around here I began thinking he's led me into a trap.

The river was the 3 of diamonds. Now, he bets out 25 bucks. I'm positive the 3 couldnt have helped him, but did any of the other cards? Should I think he's just taking a stab at it by making it look like he was trapping the whole time? Was I an idiot for playing fours this strongly?