Writing Fanfiction While With a BF/GF

Does anyone think it wrong or cheating that someone writes fan-fiction while they are with someone?

I have found that even though I am with someone, I can't help but read and write fan-fiction. I am about Loki and I am about Bucky Barnes right now. I was a little embarrassed about it when I was writing my Loki stories, but I quickly got over it because my boyfriend was actually being a bit supportive in it.

But now I am writing one about Bucky Barnes and I am just so embarrassed by it, and I don't even want him to know I am writing fan-fiction any more.

When we first got together, three years ago, I hadn't read or wrote any fan-fiction at all for like a good year, but then I found myself wanting to read and write it again.

Today is what really got me into thinking it was wrong. I began a Bucky Barnes story and I tried to make it so secretive, but one of my papers that had some ideas about it fell in the floor and he read it.

So, now I feel really depressed because I feel like he believes that I would rather want Bucky Barnes or Sebastian Stan than him, and its not like that at all. If I had the chance to pick him, Bucky Barnes, Loki, Tom Hiddleston, or Sebastian Stan, I would pick my boyfriend.

So my question is this: "Is it wrong that I write and read fan-fiction while with a boyfriend?"