Slightly different because my Fiancé is another guy, but -
After 5 years I found the most success in getting him involved. I bought another cold wallet (needed a new one anyway) and had him set it up (with my help)
His computer, he went through the motions, we spent time hiding the seed phrase (he found this part exciting lol)
Finally I sent a healthy chunk to the wallet so he could see it and feel part of it.
He still is probably at 20% in terms of understanding the importance, but now he is excited about it!