I've been a part of a happy long-term relationship over the past 4-5 years, and we've been engaged for some of that. The relationship started when I moved to a new town, so I left a lot of my life behind, including a certain hobby, a competitive card game (not gambling). We're currently pretty settled, we have a few pets and live together in the same house.
The 'hobby' has a reputation for being an expensive one, but I'd always been stingy with it and didn't spend anywhere near as much as others often do. I wouldn't need to spend money to return to it, as I still have my old decks.
Fast forward to about a year ago, as I started to feel more and more comfortable and settled I brought up the idea that I might pick the hobby back up again. The response I got was at best mixed, and the ensuing argument ended up with my partner saying how they just "hate" the hobby, citing the associated expense and the fact that I'd changed a lot since I last did it. Honestly I don't consider myself to have changed at all since I regained an interest (passion?) in the hobby. If there is a more fundamental or reason than that then it's never been mentioned. I feel like I don't understand the problem they see. These feelings seem to have been exacerbated by the fact that I'm now out-of-work, and while I wouldn't spend anything financially on the hobby given that fact, I receive responses like 'I'm not happy to be paying the rent if you're going to waste your time on [hobby]' if it is brought up again.
As a result of them making me feel bad about it, I've essentially been committing time to the hobby in secret, while they're at work etc. I feel incredibly guilty for more-or-less lying to them like this, but I feel that I should have a right to pursue something that makes me happy and being secretive about it seems to make us both happy.
Subsequent times when the hobby has just randomly come up in conversation, my fiancée has been extremely derogatory, but I didn't say anything other than nodding my head essentially, as I didn't want to re-open the issue even though this was making me feel pretty awful.
Essentially I have no idea what to do. If I'm frank and honest with them then I'm afraid it will all end, and I feel that we're so good together and settled. I feel like I don't want to have to cut out a thing that I really enjoy because of my partner's seemingly irrational hatred, since it would also cut off a significant portion of my friendships from where I first lived.
I feel so guilty for how I'm acting because of this, and just want to have an honest relationship again, but I'm afraid that will never happen again with them.
It feels like just cutting myself off from the hobby would fix everything, but it's a social hobby and I find it somewhat difficult to start friendships in other ways.
How can I have an honest conversation with my partner about my hobby, to understand why they hate it and express why it is important and beneficial for me?