Since people here have mentioned phone slip-ups, I'll sneak this one in here:
My dad met his best friend 'D' when they were coworkers in the military. Later when they both had moved on and settled in different states, Dad's buddy would call our house to keep in touch. He was good friends with my mom too so if she answered the phone, D had this joke with her where he would pretend to be a "mash caller" and breathe heavy into the phone, etc. and she would laugh and tell him "I'll get *Dadsname* for you"...
then one night I
answered the phone.
I don't remember how old I was (IIRC somewhere between 9-11yrs), but I do know I was not in on the joke, nor was I old enough to understand what the heavy breathing was about.
He said in this faux-'naughty' voice something like "What are you up to sweetie?" I was confused since he hadn't identified himself and I didn't recognize his voice, so I was like "Um, what? Uh...I don't know." Then he said "*Momsname*?" and I said "No this is *Softly*" and he was mortified
and said "Oh I'm sorry honey! This is D, can I talk to your Daddy?" I got my Dad and apparently D confessed his mistake because Dad listened for a second and then just about died laughing. He had mom explain the joke and then I got to tease D if I answered the phone when he called.