"I feel that it is presumptuous of me to bring my guitar into someone's home or wherever without having been asked." Got a good dodge for that. Bring it in anyway. Explain that you were just at a practice, just got it back from the repair shop, whatever; explain that you never leave it in the car and is there a corner you can hide it in where it won't be in the way. That way, its presence can be safely ignored if you wish, but your (& their) options remain open. Only just a tiny teensy bit devious, methinks.

Why am I reminded of the button I got for 50th b-day that said, "Experience & treachery will always overcome youth & vigour"?