This is going to be quite specific to him, since it plays to his (usually secret) fantasies. So the idea here is for the two of you to share you "secret sex fantasies"... that would really help.
Yeah, there are definitely some common fantasies - check out
'http://forum.askdanandjennifer.com/topic/what-is-everyones-biggest-sex-fantasy' from
'http://forum.askdanandjennifer.com/topic/null' Forum here.
But I think they key here - and a wonderful thing for you two to do as a couple is to share you secret fantasies with one another.
Something we recommend for that is making a "fantasy box" - where you each put one piece of paper with one special fantasy... or ideally you each put a lot of them.
Then every now and then - maybe on Friday nights - you take turns who gets to pull out a fantasy from the box - and see if you both feel up to trying it. That way there's a lot less pressure, and it can be a lot of fun for you as a couple.