You’d think it’s the one thing you can’t possibly lie about: pregnancy.

Yet many women have admitted to faking pregnancies on the anonymous confession site Whisper, and their reasons are varied.

“I pretended to be pregnant just so my boyfriend would stay with me,” one woman said.

“I lied about being pregnant just to make my boyfriend happy,” another added.

Examples of silicon pregnancy bellies. Source: Getty Images.

One woman said she pretended to be with child so it would have the opposite effect.

"My ex sucked in bed. Freaked out so I lied and said I was pregnant - from my previous relationship. Couldn't tell him the truth," she explained.(Post continues after gallery.)

Celebrities who are expecting.

Sonia Kruger

Blake Lively

Duchess Catherine

Amanda Peet

Princess Charlene of Monaco

Kourtney Kardashian

Kelly Rowland

Duchess Catherine

Zoe Saldana

Hayden Panettiere

Gwen Stefani

Asher Keddie

Liv Tyler

Kirsten Bell

Mila Jovovich

The reasons weren't all man-focused, mind you, with some revealing a concerning level of, well, selfishness.

"I faked a pregnancy at my last job to get time off work," one woman said.

"I faked a pregnancy and a miscarriage just so my boyfriend would propose to me," another admitted.

Remember when people thought Beyonce was faking a pregnancy? Ridiculous. Source: Getty Images.

Some users pretended they were expecting a mini-me for rather creative perks.

"I pretended to be pregnant on a plane so I could use the bathroom in first class," one woman said.

"I pretended to be pregnant to get my traffic ticket dropped," another admitted.

Mamamia staff reveal the biggest lies they've told their partners.