physical union of male and female genitalia accompanied by rhythmic movements usually leading to the ejaculation of semen from the penis into the female reproductive tract
Example: Kris Ann's sister was shocked when I informed her that we were preparing to engage in coitus.
Scientific reference for 'doing the dirty', having a 'no pants dance', or advancing courtship. Coitus is commonly used in a popular TV show, The Big Bang Theory.
Example: Penny: *opens door* "Hey, my power's out, can I stay here for the night?" Sheldon: "Do you really-" Leonard: "YES, of course...th-that's what friends are for, after all. Lending a room in a time of need."
Sheldon: "Well...as long as this doesn't end up in Leonard and Penny taking part in coitus, I guess I can live with it for one night."
Example: Little Joey at 7 years old: Coitus, stop eating paste.
Little Curtis at 7 years old: Stop calling me that, fuckhead. Don't you know what that means yet?! And this paste is delicious, so hop off my nuts.
Sexual intercourse, where the male inserts his penis in to the female's vagina. The majority of males are stimulated in to ejaculating liquid filled with millions of semen.
Example: Barney: Yeah let's have sex. Sesame Street chick: Sex?
Barney: Coitus. Or oral sex?
Sesame Street chick: Yes. mmmm... nom nom nom.
(_(_)!!!!!!D ---> O: