Tell your wife before you become intimate again you will need her to be tested for STDs. This is to protect yourself. Who knows what OM may have given your W (besides a baby). I've read of others here being infected by returning S so this is IMPORTANT.
I don't see a reason to go dark on your wife. Like Puppy, I agree that she's untrustworthy and just reaching out for any man (you) because she finally realizes these other guys don't want her at this point and you are all she has. But now is your chance to offer some support. I don't see how pushing away, or going dark at this time would help you. I personally think you need to be a friend and just go slow about reconnecting. Keep some distance FOR YOU and your sanity. So you can feel comfortable. You both have a lot of healing to go through. Tell her you need to go slowly to redevelop friendship and trust. Tell her you have a child together and she can always count on you to be there. You won't turn your back (like OM), but you need time and space to heal.
There is no arriving, ever. It is all a continual becoming.