Nick's Sleeping Arrangements

I'm curious, why was Nick sleeping on the sofa, or at Monroe's house, when they had a whole guest bedroom available upstairs? When Nick & Juliette were going through their issues, after her memory loss, she did not want him sleeping with her. Understandable. But, Nick was sleeping on the sofa, covered in the blanket Bud's wife made for them, before moving to Monroe's house. Why not just sleep in the other room? I didn't notice it before but I'm noticing it on my re-watch.