Women fake orgasms more frequently than men, with a whopping 26% claiming they've done it in bed.

And since it's common for females to lie about their satisfaction under the sheets, it can be difficult to spot when it's genuine.

One fella is questioning whether or not his ex-lovers' have faked an orgasm during sex.

Writing to news.com.au's Relationship Rehab column, the anonymous teenager candidly discussed his kinky antics.

He said: "I'm a 19-year-old guy and I've only had sex with three girls, all of which were casual flings.

"I'm just wondering how you know when a girl's had an orgasm?"

He wants to make sure women aren't faking it with him
He wants to make sure women aren't faking it with him

The teen continued: "I've heard lots about faking it and want to make sure that isn't happening to me."

Fortunately for the fella, his sexual dilemma was answered by the publication's sexologist Isiah McKimmie.

She told him it's often a challenge to spot whether or not a woman has had an orgasm.

And she did give the teenager some advice.

The 19-year-old revealed he's had three casual flings
The 19-year-old revealed he's had three casual flings

The sexpert said: "The challenge is, that there's almost no definable way to tell whether a woman (or man) has had an orgasm.

"There's no single physical indicator that defines orgasm (yes, even for men, as ejaculation and orgasms are not the same process).

"The best way to find out whether a woman is enjoying herself is to create a sense of safety and good communication between you."

She did warn faking an orgasm is something that happens a lot but by asking her what she enjoys in bed is good way to start.

There are a lot of reasons why females aren't genuine about their sexual satisfaction.

Previously, a sex doctor revealed four reasons why women fake orgasms when they shouldn't.

Dr Emily Morse said some lie about the Big-O to "please their partner" or because they think they're "expected to orgasm".

Some ladies will also pretend to climax to "end sex early" or because they "don’t think it's going to happen" anyway.