I've been to a comfort level beyond even that, and like a visit to Madame le Guillotine there's no going back. In college I had an extremely hot female-friend break down and cry one night after a disappointing (for her) breakup with some stupid frat-boy. While literally crying on my shoulder, she said, "why can't I find someone who'll treat me right? Someone who will hold me and love me and really know who I am, like you do. Why do I always end up with these jerks?"
There could've been a large flashing marquee over my head and she would've missed it. She was so comfortable with me that she would change clothes (down to her underwear) right in front of me. She did make me face the other direction when going topless...... right before she lied face down on the bed, had me straddle her butt, break out the oils, and give her an excellent massage. (That was a regular occurence).
She eventually did see me in a new light.......... once I was engaged!!