Tub surround sticking out help!

[Thomas Wallace]

I recently tore out our old tile and put in a 3 piece surround. I didn't notice I was going to have an issue until it was too late. The outside corner isn't wide enough for the wall. I'm at a loss at a reasonable way to make it look presentable. Any help would be greatly appreciated.

 

[Terry]

You still have the valve end panel to install right?
You might need to add some wood backing there.