69

Think of the circles in the number 6 and 9 to be a human head. Now image the other part of the number 6 and 9 to be genitalia. As you can see, the 6 is shoving it's cock down the 9's throat will the 9 is getting it's pussy licked by the 6. Essentially, a 69 is when two loving human beings position themselves in such a way that looks like the number 69, and allows them to "Go down on each other" simultaneously.

Oh my god, Karoilna and Will 69nd last night.