I am assuming you are talking about the problem of him wanting the changeling child when Titania has him.
Well, since Oberon uses the juice fromt the Love in Idleness flower to make Titania fall in love with the ass that is Bottom transformed, I think it is cowardly.
Instead of working things out with Titania in a civilized, adult manner, he tricks her into getting distracted by a false love so that he can steal the child for himself. As the powerful King of the Fairies, I would think that he could have done something much more above board and bold...or he could have compromised with her.
It's like a brother saying to a sister, "Hey, look over there.", and then stealing her cookie when she was distracted. It just seems out of character for Oberon to handle the problem in this way.