The Mr. and I discussed this the other day when I asked him about the baking cookies scenario brought up in the ED thread. At the moment it's just something he's not comfortable with. It's not about a relationship developing; it's that he's my protector. On the small chance the guy gets too rough with me, he wants to be there to kick ass.
I hadn't thought of the bathroom thing, though. If he's not done and I gotta pee....
Even if safety weren't a concern, we'd probably still be same room. For all the reasons Spoo put so nicely.