If you're in a long-term relationship you're likely sick to death of people asking when you plan on getting married/having kids, but spare a thought for the poor Danes.

Denmark is known for its low birth rate, so anyone of child-bearing age is probably getting hounded on a daily basis to start a family.

Now one travel company has come up with a solution for the country's aging population issues… kinda.

A new ad, aimed at older parents who are just gagging for a grandchild, suggests they pay for their child to go on an "active holiday," with the hope they'll spend lots of time between the sheets.

The logic? People are more likely to have sex on a sunny holiday.

Plus, couples who break a sweat together are apparently proven to have more sex too.

"You were there when your son learned how to walk, but when it comes to making grandchildren it might be a little awkward to help out," the ad says.

"Maybe it's time to get a little proactive."

Would-be grandparents can purchase a Spies Travel holiday for their child – be they single or attached – in the hope that they'll be inspired to get down and dirty. 

The Do It For Mom campaign is a follow on from the Do It For Denmark campaign in 2014, which offered an "ovulation discount" to any couples planning a romantic city break.

An ovulation discount? We could get on board with that.