Even if you're out of ketosis, it's not something to worry about. For example, I ate a cookie last week. Somebody baked their own cookies and asked me to taste it. I didn't want to be an asshole so I did. Then I moved on. Like you, I also do not seek to lose weight. So it's not like it'd be interrupting a weight loss journey of the kind. Once you're fat adapted it's much easier to go in and out of keto, I've been at it for nearly a year now, so I am not worried.
The cookie was ok, said it was amazing. But I did not want more, I did not like the effect it had on me. The shackles of sugar are slowly eroding.