Experiencing the visit of my monthly friend at work, I trudged out into the kiln today, across the car park to the little shop in search of some tampons.

"Office sex; I've never done it, but Kat tells me it's amazing. We'll have to try it once my monthly friend leaves."

“That's what you're trying to do. You're trying to get pregnant!”
“I'm not! If it happens, I'll be glad. If not...”
“You're disappointed every time your monthly friend comes to visit. Will anyone else be glad if you got pregnant?”

Monthly friend

Meaning

Noun