I would like to address one thing before I answer your question, if I may.
If you're getting these kinds of questions, it may because you're creating a situation where spectators are challenged to look for a secret. This can be because you are challenging them with your magic, or you are performing for people are not interested in seeing a trick. I am stating the latter because you said you do magic all the time, and people can become sick of that if you are consistently trying to do a trick for them.
I sometimes ask people if they would like to see a trick, yes, but I more than often wait for people to ask to be shown a trick. I would even wait until they've asked me a couple times, that way I know that they really would like to see something and will often, if not always, respond well to it.
Now if I were ever asked about using my sleeves, I would go into Sleeve Aces or Collins Aces, which I learned through Michael Ammar's "Easy to Master Card Miracles." I would prefer doing Collins Aces because I can do it after any Ace production and I know the trick so well I dont even have to look at the cards. This has the type of false explanation thing that you like, but in a playful way that provides justification for what you're doing and seemingly creates the magic.
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Hope this helps you, and welcome to the forums!
-Andrew