From vanilla to daddy - how to?

So im the freak in our house and my husband of 4 yrs is super vanilla 😂. I love him, his gentleness and how he cares for us (me and the cats) but soemtimes a lil part in me want him to be kinkier. Ive tried talking about this and it hasnt gone wrll. I think he was brougt up to see that as wrong. Any ideas on how to encourage him?