When your girlfriend looks exactly like your twin daughters.

Take a look at the above photo. Three of the people in it are related, and that includes the guy. Go on, you can scratch your head now.

The puzzling family happy snap was posted on Instagram by a British actor named Dean Gaffney, along with the following caption: “Everyman [sic] needs a good women behind him… I have 3!!!! #daughters #GF”.

Confused? So is the rest of the internet.

“I can’t tell which are daughters and which is girlfriend!” wrote one commenter beneath the post. “Legit don’t know which is which,” wrote another.

Here’s a clue: the 39-year-old’s daughters are twins.

Nope? Still nothing?

Okay, well how about this: the twins are 19 and the girlfriend is 23.

Still not sure?

We’ll let Gaffney – who was once on Eastenders – solve this riddle himself.

Yep, the girlfriend is the one on the left of the image. Her name is Rebekah Ward, and she's a model from Peterborough in East England.

You're welcome.