If you can come up with something, what would be YOUR answer to your question. In other words, what could your W do "around" the act of assembling a jigsaw puzzle that would make you have a passion for jigsaw puzzles (figuratively)?
She could have her hand down my pants and giving me squeezes while doing the jigsaw puzzle. OK, otherwise she could just have a sense of humor, talk about stuff, flirt, or challenge me to help with some aspect of the puzzle.
Not sure where this is going because my wife is happy with all the things that are traditionally supposed to make ANY WOMAN melt and want to jump her husband. But that just ain't so in our case. I don't know how to build more of non-sexual context that could be conducive to sex.