A variety of factors - from stress to pornography - can cause couples to have less sex, a relationship counsellor has said.

Gen Z and millennials often make headlines for reportedly having less sex than their older counterparts, but couples of all ages can experience sexless relationships.

That's according to relationship counsellor and psychosexual therapist, Eithne Bacuzzi who advises many couples on sex and intimacy. 

On Moncrieff, Ms Bacuzzi said there is a "myriad of reasons" behind why some couples avoid sex.

"Often couples have stressful jobs, children and fatigue, and there's just not enough time," she said.

"Sex requires time and attention and that starts outside of the bedroom, because you can't just not talk to each other for a week and then say 'let's do something.'"

Ms Bacuzzi said couples need to date in order to strengthen their connection and to prevent sex from becoming "clinical".

"When the subject degenerates to 'Are we going to do it tonight?', then the couple are in trouble," she said.

Pornography

Another factor that could be impacting a couple's sex-life is pornography, according to Ms Bacuzzi.

"It creates unrealistic expectations," she said.

"Sex is about giving and receiving and porn is too easy - you lose out on all the other bits."

Ms Bacuzzi said, however, that if a couple are on the same page when it comes to pornography, then it might not affect their relationship.

Rejection

Couples who are in sexless relationships may experience low self-esteem or feelings of rejection.

"One person feels rejected and the other feels pursued, and that's a very painful place to be," she said.

"The first thing I would say is we are responsible for our own sexuality and we can't depend on anyone else."

In these instances, Ms Bacuzzi recommends therapy to help the couple discover what other issues may be lying beneath the surface.

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Feature image shows a couple in bed, Alamy.