I don't think Meredith was ready for a relationship - that's why she kept pushing it away. Until recently it was just a hook up. What no one will admit is she is using Maggie as the reason - when really it was McDreamy's Ghost.

Maggie is Riggs direct supervisor/boss. Kinda fail to see why this hasn't been brought up as an issue - or at least a reason for Nathan to use to stop her from crushing on him.