We have a president, not a king. That means he is in charge of the executive, nothing more. Congress is a totally seperate entity.
Congress invited Netanyahu to come speak, as it had a right to do. They are in no way obligated to get the nod of approval from the executive.
If anything, the whining and crying from Obama and the left stand out. This isn't about you, obama, or your ego. America is more than just Barak Obama...American government is more than just Barak Obama....and the fact that his feelings got hurt or that the dems wanted to act like spoiled children who didn't get their way means nothing.
The bottom line is that congress, as it is more than legally entitled to do, requested that Netanyahu come speak before them. He accepted the request. Obama should have just ignored it, instead he pitched a fit and stomped his feet and got nowhere.