Grandma, Mom and I all went together for a "Girl's Weekend". We would travel to some nice spot, like the coast, go see the sights, have a meal or two, chat, vegetate, and then head home.
Like always, Mom and Grandma were having the continued 'discussion' on why Grandma should stop smoking. Grandma and she would go round and round, and when we'd stop, she light up again. Mom had tried various means from the virtuous, to somewhat nefarious, to stop her habit, to no avail.
For whatever reason, they were making a bit of a row about it. I was just observing, more than anything. I didn't want her to smoke, either, but knowing the stubborn streak of the females in our family, I wasn't about to put my two cents in at that point.
We arrived at the hotel, and had put most of our things in the room. Mom had laid down on the bed and was reading, and Grandma was sitting in a chair nearby. I went out to check that the car was locked, and Grandma said something to Mom. I was reasonably certain that it was that she was going to go have a smoke. Mom protested, Grandma studiously ignored, stepping outside the door. I leaned against the Subaru, talking with Grandma.
We heard, "I am NOT letting you in!" And with that, Mom closed and locked the door. I was rather surprised, but Grandma got an incredibly wicked 'we'll see about that' grin, and took another puff. Then she walked to the direct center of the window, and MOONED my mom, still grinning. In fact, I think she took another quick drag on the cigarette. I actually don't know for sure, because I was braying with laughter.
I don't know that I have seen my Mom move so fast. The door opened, her arm reached around the corner, growling "Get IN here," and she dragged Grandma in so fast, she couldn't pull her pants up, and sort of crab walked her way back in.
I wasn't high on anyone's list for a few minutes, mostly because I couldn't keep a straight face.
Finally I got control of myself, until Grandma piped up, "Oh, and I am back in."
Whereupon I lost it again...
And she finished the cigarette, too.
(Much later, she did stop smoking, but the memory of Grandma's Full Moon lives on...)