Is it immoral if I don't tell my fiance about this account?

As an old married guy, I think hiding pretty much anything other than a birthday present is a bad idea. When you find out someone you're in a relationship with was hiding something from you, you're likely to feel betrayed even if you didn't care about the things itself. You start wondering what else the person is keeping from you. Trust is hard to regain.

Add to that, if you marry someone you can't be 100% yourself with, you're setting yourself up for an unsatisfying relationship. If, down the road after marriage, you admit to something about yourself that you kept to yourself, it's pretty unfair to the other person, and if you never admit it, it's unfair to yourself.

First, be gentle with yourself. I think if you are marrying someone, you want them to know about all the aspects of your sexuality even if they feel neutral about some of them.

I think you will just have to straight up tell her one of your pleasures is posting pics online, first ask if she likes to do that herself, ask if she wants to see yours when you do. If you personally don't think you've done anything that crosses a line please don't borrow trouble. As long as you are ok if she enjoys the same, I think you are good. Sooner is better for this.

Oh, and I know you say that the relationship is more important than the kink, but you are a whole package. You can't be someone else, she is getting you. You say that embracing this side of your sexuality has brought you confidence, it must be important. What you are saying (I think) is that you don't need her to be enthusiastic and turned on by it, or directly participate, you can easily enjoy sex with her however she likes or needs, and be satisfied and happy, that makes sense. But you do need her to love you for who you are.

First of all, don't delete everything. I'd just create a new account. Deleting stuff on Lemmy just doesn't work that well. All your contributions and all the contributions from people who replied to you just vanish. And people might still want to read it if you did more than just shitposting... (But maybe this is your way if you want the pics of you gone.)

I have about 3 accounts. And I separate NSFW stuff, stuff I'd be ashamed of, being helpful and answering Linux questions and mundane political discussions and memes. At least a bit.

Concerning the relationship: If you want my opinion, a healthy and grownup way to treat each other is to communicate well, talk about wants and needs, opinions... But also to have your own space and privacy. So it's neither - nor... I don't like to tell my spouse how exactly I masturbate when that's "me time" or which porn genre I consume how often. But I put in some effort to talk about how I feel, what I'd like to try together etc. Neither of us wants to give up our individuality and independence. However we treat each other with respect and know 100% that we can rely on each other. But each of us also gets to have some small "own" things. And I think that's how it should be. But of course it completely depends on the personality of the two (or more) people. And you need to agree on that. It doesn't work if one of the involved people is a bit controlling. But I mean you can also forget about the non-monogamy if someone is controlling or jealous.

So summed up, it's not hiding in our view and it's not big things. It's more giving each other room to breathe and be ourselves. And it goes both ways and is agreed on by all parties, which is the most important bit. If you can talk about everything with your partner, just bring it up. Ask if it's okay to have some space that you don't share and do whatever you like with a second (your current) account.

Edit: And since I've now read a few other opinions... I'd agree on the 'take it slow' part. You need to figure out how to be you. And how to be comfortable with what you are. And on top you need to figure out how to communicate that. It's not easy in general. Do one thing at a time. Take your time. Don't hide from your partner, but also don't ask too much of them or yourself all at once. I'd say get things rolling first, that's difficult enough and then see that things are going into the right direction. And everyone is different and needs to agree on different things. I for example wouldn't like sharing pics online. And I'd feed bad if my partner did that for years already and didn't talk to me about that. It wouldn't be a dealbreaker, but I wouldn't feel valued as a partner if that were hidden from me. I mean I also wouldn't ask them to stop, but I'd just like to know things like that... In the end everyone has boundaries and their own conception of a relationship. There is no way around talking to each other. The sooner the better. But also don't do silly things if it's too late. Fix it at some point, beg for forgiveness and do it right in the future. A secret fetish or posting nudes isn't on the same level as cheating (for example.) I can't comment on if lying by omission or 'the end justifies the means' is something you're comfortable with... I wouldn't do it for prolonged periods. It's not how you build a relationship that includes the freedom and variety you're after.

Edit2: And if you have issues discussing intimate stuff... Have you tried writing it down? It sometimes helps me with difficult topics. Write a letter, explain yourself and include your complicated feelings. Put it in a drawer for 2 days then read it again. Then you can either rework it, throw it away or wait for a good moment to give it to your partner. Have them ask follow-up questions or tell their side of the story.

I wish I could say that there was a one size fits all answer to your questions, but the reality is that it really all comes down to your existing relationship and the boundaries that you've both discussed together. What's considered cheating is a nebulous concept - some couples might consider simply watching porn cheating whiles others are fine with having multiple partners.

I'm just scared of rejection and our relationship is more important than any kinky stuff.

You need to ask yourself if you would be comfortable being in a relationship where you always need to be hiding a part of yourself. I've tried it and honestly repressing these things have a way of manifesting problems regardless. Kink in general is about learning to accept and express the parts of ourselves that we usually keep locked away. I was terrified at first to tell my partner I even wanted to shave, but all she did was covertly ask if I'd prefer feminine pronouns. Now we almost always have matching manicures lol.

1. You haven't screwed yourself, but you should approach the conversation with the care and tact it deserves. Anxiety or not, these are difficult conversations that need to be had. Maybe it's not as bad as it once was, but we live in a world where a lot of behavior outside the hetero masculine norm are heavily stigmatized and posting pictures has been an outlet to express yourself where you otherwise can't.

2. If I were told I'd be skeptical, but I wouldn't personally be mad if my partner(cis female partner, me a bi queer man) came to me and said she was taking and safely posting boudoir photos for an exhibitionist thrill. I would understand, but I would be a little hurt and disappointed that she chose to not to include me in that part of her life though regardless of my feelings on the content.

3. Truthfully if this is something that would be a huge paradigm shift for your relationship I would say to ease yourself into it. Start by introducing chastity or (safe)exhibitionism into your current bedroom play. Maybe set up a couples Fet account and see what you both learn about one another in the process. I wish I could offer advice about breaking the news about crossdressing, but that's a hurdle I haven't come over completely myself.

Good luck.

i dont know if its immoral. im a woman and i would more feel weird that my SO wanted to hide anything from me. i dont care if he watches porn or jerks it or flaunts it. hell i dont think id even care if he fucks another woman, so long as it doesnt effect our relationship and is transparent about it. maybe im unusual in that way because im very left wing, i dont know.