I don't get a sense, from these posts, of what the problem is with your wife, I mean the concrete problem. You say you are 'bored', but what is boring about her, her conversation, the things you do on weekend, do you find family life dull with a small child? What could she do differently, if you were to wave a magic wand?
See, my husband isn't really there to entertain me and make my life interesting. I do like him a lot, but if he wasn't there, my life would still be interesting, as I have a great and intellectually demanding job, good friends, have fun/downtime which I enjoy and so on.
I wonder why your life's dullness is all down to your wife, and what you imagine swapping her in for someone else would be like.
The small child stage isn't for everyone, and you do get a lot more freedom when they are older/self-entertaining, although obviously they need lots of emotional attention/lifts everywhere!
You sound like a man on the verge of a mid-life crisis, who can't quite get over that he isn't the hottest, most successful guy around that he thought he'd be by this age, and is looking for some excitement (affair, flirting with younger women) to sustain his dull life.
I may be reading this wrong though, perhaps your life with your wife is very dull or you have just gone off her in an not repairable way (e.g. don't fancy her any more) in which case, it may be better to move on.