@diegovmolina,
Diego,
I'm sorry to hear of your situation. It must be rather difficult to deal with.
Let's get a the reason out of the road first, because it is probably important to you - you may have grown apart (and your wife became bored or lonely or both), or you may have neglected your wife's needs over many years (and she became bored or lonely or both). Either way, she has made a conscious and complete break from you.
This is tough, but personally, I'd change the locks and move her out.
There's some very good reasons for this.
- Firstly, she has lied to you for quite some time - this shows disrespect (she didn't want you to make the decision you were entitled - that is, leaving her when she started seeing another man. Secondly, she can't lie to you and have you believe her, without losing respect for you).
- She likely left you on a pretence, which again shows little respect
- You say she's treating you like dirt...again, little to no respect.
- You have a child witnessing his mother treating you this way. He will 'learn' lessons from this, and how you react. If you react as if you aren't worthy of respect, then he will learn a lesson from that. If you react and treat his mother with disrespect, then he will learn a lesson from that.
- Your child is witnessing his mother going out with another man, yet coming home to your bed...this will confuse the hell out of him. Especially as you allow it.
- show your child that he should always stand up for himself and respect himself, and expect others to treat him with respect (it's okay if they have a problem with him because we all have faults, just so long as they express their problem respectfully)
But mostly, you need to do it for your own self-respect, no matter how much it hurts. By allowing her to stay, you are saying 'I deserve this' (it doesn't matter how much logic says you don't...by allowing her to stay, you have to justify it to yourself, and there's only one emotional way to do that - have a look inside yourself next time she comes home, and see what you feel).
Lastly...by kicking her out, she may come to realise what she's lost (I've seen that happen before). And it may give you time to think about who you are, who you want to be, and where you are going.
Good luck