I think Stuart did start off wanting to get close to Michelle but I think I could detect him getting irritated with some of her comments during their conversation in bed.
I also think he probably believes in sexual equality and doesn't mind a girl making the first move but I think he thinks she's being *too* persistent. After all, think of it the other way round. If Stuart had got into bed with Michelle while she was trying to rest, asked her if she was a bit the other way because she wore trousers, and then tried to get her to take her knickers off afer only knowing her for 4 days, we'd say he was harrassing her.
As Stuart doesn't seem to be a "get it wherever you can" type of man he might find Michelle's approach overbearing.