I wouldn't call it rape, no. But I would certainly be holding back from becoming physical with such a woman - really with any woman. Once sex starts happening the relationship gets cloudy. I'm of the opinion that you let the relationship develop before you add in sex. Obviously not everyone agrees on that, and there have certainly been times I did not wait. But all in all that's where I've seen the most success happen.
If you were just looking for someone to keep the bed warm while going through your divorce, I imagine that's a bit different, but I still see Sharon as a woman who has been used and abused and doesn't know her worth. You'd be a better man, in my opinion, to not have sex - especially with a woman like that - unless your intentions were above reproach. Most would see a woman like that and believe she's worthy of less. I see a woman like that and know she deserves much more than she's been given.