When I used to hear the phrase "eating out"--used to refer to oral sex--I thought you could only do it once, because afterward your genitals would be eaten and gone.
A childhood belief about oral sex

others believed things like this
- I believed that oral sex was people having sex in space.
I think I got 'oral' mixed up with 'astral'— PinkPanther - As a youngster, my older brother told me that polish sausage was really the bull's genitals. — Ross
- When I was seven, I thought oral sex was when you talked about sex.Anon
- I thought that 'oral sex' was just French kissing.— Rachel
- i seriously thought that oral sex was making out. who knew— shannan
- i thought that the phrase "jet lag" was actually "jet leg" until i was 17...— truffles