Yes! an interesting post!
How to heat up things to being like bunnies again.
Grant her a fantasy. Ask her to grant you a fantasy. Both willing, of course. (suggestion: as incredible as it may sound, teasing with S&M works. tie her up and let her crave for you.)
Play games. Like "guess the sex favor with mimic" game. No touching until one of you guesses and then the favor is granted.
Have sex outside. On the roof of a building (or your house), in a public park, or a quickie in the elevator. Ignore people that want to get in. Just press the "close door" button and keep going till the last floor and back.
Anything else? Share your ideas with her and explore your imagination.