Changing rhythm

Most men like a bit of a stop-and-start rhythm when they're having sex, simply because it's in their nature and how they function. So they can start to think that their partner also likes the same rhythm...or, worse perhaps, in the heat of the moment they stop thinking about what we want.  

Most women are just as sensitive to slow rhythms as they are to fast ones, but of course men aren't going to know that! 

Explain that taking it slowly often equals more pleasure for you, and it will also prolong it for him, so it's in both your interests to vary things a bit!