It 's kinda hard to explain but i will try.
A couple of my cousins were doing some scratch-off art thing and they told my grandmother something like "we are using the scratch art", so i whispered to myself "oh yeah? Well you can scratch-off my balls" (i whispered it to myself dw), but my sister heard me and was all like "that's inappropriate, don't say that". (I then kept on making fun of her for it).
So that's it, it was just some bland ball joke that wasn't even all that funny that my sister got mad over for no reason.