Engineers in Iceland have made a smartphone application to help users see whether they are dating a relative.
With the slogan "bump the app before you bump in bed" the Islendingabók app allows users to access an online registry which acts as a giant family tree for the whole country, News of Iceland reports.
By bumping their phones together, users can see how closely they're related, and whether it's too close to take things further.
But the reason the app is such a good idea is because everyone in Iceland is a little bit related.
The country's population is small enough for everyone to come from the same family tree, but large enough that not everyone knows one another.
Meaning accidents can happen with cousins. And they have.
News of Iceland reports one user commented on the app's website: "If I would have had this app last year I probably wouldn't have gone home with my cousin."
The app is only available to Icelandic citizens and available on Andriod phones.
