Well, I have no easy answer for you.
Just remember that crying is only a child expressing his opinion.
It's up to YOU to decide if that opinion is correct or not and whether it deserves attention.
Of course, responding to crying is BUILT INTO us biologically and can't be ignored.
But your logical brain should always trump biology.
Your job as a parent is to decide IF anything should be done about a cry, and then either do it and see what happens...
Or... You know, just grin and bear it... It's what we parents have to do...:)
So try not to respond instantly to a cry.
It's pretty difficult to do, but you've got to use your logic, not just always cave to your biology...:)
At 3, your son should be walking. He should be exploring more things than just his Mom.
Make the little guy walk to GET to Mom.
Stuff like that.
But, really, nobody but you and your wife can truly answer that question :)
Good luck to ya !