One I remember was when I first started dating my ex. My mom worked til 5 so I had an empty house after school. So of course I made good use of that, and then we would flush the condoms.
Well, it isn't a good idea to flush condoms. I remember coming home one day and my mom asked me if I was having sex. I lied and said of course not even though he wasn't my first and have been for a few years.
She promptly let me know that a "rubber" came back up in the toilet. Then she told me if I get pregnant, I'm out on my butt and I had to keep the door to my room open every time he came over.
Hearing my mom say rubber was mortifying back then. I was 15 and it wasn't the slang of my generation.