Speaking very generally, at his age, they don't see good parent/bad parent. They want security and who is the parent that gives them that security; that is what they respond to. So if your wife is inconsistent, it would make sense that he would act out as he isn't secure with her at times.
If she has always been that way with him then no he won't really see her as being 'off', he just figures this is how she is. He has figured out one way to act with her and another way with you to feel secure.
Originally Posted by
Shellcrusher 
After reading HoopNinja's thread I've been wondering about something.
My therapist said I was an empath, meaning I can pick up on emotions. (I also take ownership of them but that's a different thing.)
There have been times when I was stressed out. Probably angry with my AW. She loved to wield my boy like a axe or use him as a shield in the bad times. She'd make comments to me that my son is picking up on my energy and it's making him upset. I never liked hearing that because I can believe it. Even more so based on the comment my therapist said.
Skip to current events. I've noticed that when the AW is out doing her thing, my son is a sweet little boy. He doesn't wine. He's happy. He plays. He helps me do stuff. He's only 2 by the way. The moment the AW gets home he turns into a crybaby. Wants to be held. Won't go to bed. Gets naughty, etc. I suspect much of it has to do with inconsistency between parenting styles. He knows he can push his mom and she'll cave to his every whim.
The biggest and more extreme mood shifts with him happen on those nights when I suspect the AW is on the sauce. So here's a few questions. If you believe in people being empaths, do you think a child gets that from their parents? If so, do you think my son is reacting the way he does because he knows his mom is "off"? Ultimately, is this why, as others have stated, a child will eventually see through the BS of the drunk parent? They learn that the sober parent is good and the drunk one is bad? Even at a young age?