Could someone please explain the ending of "american beauty"?

He feels a kindred spirit with the teen, someone else who is ostracized.

Pissed off? His whole life was turning into crap. I'd be pissed off as well

Why would Lester want to have an affair with a child? Well, if you remember when he goes to see his daughter perform at the school, he first sees her friend (the blonde) and basically, in a sense, falls in love with her. Of course, he is partially blinded and ignorant to the fact of what he is doing and feeling (that she is in fact a child) and he believes that she is more mature than she really is (he thinks she has "been around the block" when in fact she is a virgin, and at the end he doesn't go through with it because he realizes that he had deluded himself about her being some princess with which to free himself, and that she, being so young, and being a virgin, and it is something that he should not do under any circumstance because of morality/ethics and punishment.

I wouldn't say that he "suddenly" wanted to have an affair with her, it's just that to him she represented the flower, the trophy, the greatest thing at that point in his life (he hated his job because he was a slave to the industry; he and his wife were not intimate and she wore the pants in the house, and he was secondary; he and his daughter no longer talked and had the relationship like they used to; essentially, everything was mundane and boring). And that is why at the first of the film he was "pissed off," but when he started smoking pot he returned to his former self/lifestyle, which finally made him happy, and after that the only reason he "erupted" from time to time was because he was sick tired of being told what to do and trampled on by his wife, so he put his foot down.

Been a while since i have seen the movie.

Why would the dad (lester) wanna suddenly have an affair with a child?

Want to say he is a mid life crisis and that would be one reason. He goes out and buy an expensive car. So figure it be along those line.

Why was he pissed off the whole time?

Probably because his wife was cheating on him and things werent going very well for him at home

Why would the dad (lester) wanna suddenly have an affair with a child?

Well, I think it was simply because he was having a midlife crisis and in reverting back to his teen years (the car, pumping iron, smoking pot) he wanted to feel young again with this girl. Not to mention he thought she was hot!

Why was he pissed off the whole time?

Because, like alot of men going thru a midlife crisis, He took a look at his life and didnt like what he say. His relationship with his wife and daughter and what he did for a living. As well as he was just plain bored with the status quo.

I think he almost went through with having an affair with a child because he saw the anguish in her eyes, and he probably felt sorry for her.

He was pissed off because he realized how much he had been taken advantage of his whole life and now he as doing something about it.