im agnostic and curious about the lifestyle, my partner is genuinely devout and its a hard line, where does that leave us

so this is an honest question and im trying to ask it without making my husband sound like a bad guy bc hes not. ive been with him 9 yrs, were both in our mid 30s, dublin based. im culturally catholic and intellectually pretty much agnostic, ive been quietly curious about the LS for about 4 yrs, ive read a lot, ive lurked here a lot, ive talked to one friend about it. he is a genuinely practising catholic. mass every sunday, daily prayer, regular confession, would describe his faith as the central thing in his life. and the LS is not just "something he's not into" — its a hard line. its incompatible with his understanding of his marriage vow, full stop. hes not angry about my curiosity, hes been kind about it when ive raised it carefully twice over the yrs, but theres no version of a conversation we can have where he would consider it. its not on the table. i love him. i dont want to leave him. but i also have this thing in me, this curiosity about the LS that has not gone away in 4 yrs of trying to make it go away, and i dont know what to do with it. its not a sex drive issue, our sex life is fine, its something more particular than that — i want to experience that kind of openness with him specifically, the conversations, the trust, the watching him with someone else, the whole architecture of it. and he genuinely cannot want that. its not stubbornness, its his soul. how do agnostic-devout couples land on this. is there a version where i let it go and the curiosity actually fades. or is this just an irreconcilable difference im going to have to choose around eventually...