We do take our SO's for granted after a while. It isn't because you're not as great anymore; it's just... well, you're not brand new. Doesn't mean we don't like you anymore; it means that we're used to you and we're feeling more comfortable so we don't feel we have to make so much an effort to please you. I don't know about "winning" someone, but it isn't like we have to woo after a period of time. :-)

Hey, if it's hitting a lull after a bit, try something different. I'm sure he too will appreciate not "the same old, same old". It certainly brings a new light into something, and probably will charge some life into him. I know my gf and I once in a while try something new, and after a while we may revert to something that we haven't done in a while.

_{DISCLAIMER: I could be talking out my arse ;-) YMMV, see store for details.}