Another one. When I was 20, I went to Cardiff with a new friend to see a band we loved.
On the day we arrived, we visited Cardiff castle and while there visited the tea room. The room was very quiet, so much so you could hear a pin drop, even with other customers being there.
My friend was chatting away to me in a lower tone than usual, when I leant in and whispered, "Can you excuse me a moment?" I got up, stepped outside the tea room doors, closed the door and let a fart out I'd been holding in.
I came back in and my friend asked what's up. I explained I needed a fart, and with that, she dissolved. She couldn't breathe, nor get her words out, I was sat there perplexed, not seeing what was so funny, I thought I was just being polite.
We ended up having to pay the bill and leave as she was in a state of hysteria. We went outside and she finally got her breath back, and said that the way I'd interrupted her and then quickly got up and left the room had confused her, but the fact that I'd stood behind the glass door looking blankly back into the tea room with no expression on my face for the 30 seconds I was out there had immediately become hilarious when she found out I'd gone to fart, as my face didn't register the effort or give away what I was doing.
I guess you had to be there. 😅