It's an interesting fantasy to paint such a fat ass green! Ladies with such an ass are especially good in the crawl position, a boner is assured. Except you have to have a decent length tool. If you don't have one, I recommend laying the lady on her back and fucking her with your hands on her thighs pressed up against her belly. Otherwise you can't get the dick in deep.
What could a blonde be thinking about? Shopping, spas and sex. And if she's offered a black dick, she'll even forget about the first two things.