Just an idea but it sounds to me that things have gotten a little stale. Have you tried any new unusual things. This can sometimes liven things up. You need to think back way back and see if there was ever any kind of hints that she may have droped at anytime of things she wanted to do. Or just totally surprise her one night or day with something totally unexpected. Have you ever sat down and got into a really personal converse with her maybe you can find out what is going on deep down with that.

Sumen