Sam Wallace confesses he has hilariously mixed up his twin daughters

It's the moment Sam Wallace has been dreading ...

He is officially no longer able to tell his identical twin daughters, Sienna and Cosette (pronounced Koh-zett), apart.

Taking to his Instagram account while on holiday this week, the father-of-three hilariously admitted the sisters - who were born weighing 2.1kg and 2.4kg but are now both over 4kgs - are now indistinguishable as they are the same size.

Alongside an adorable collection of photos of the girls, Sam wrote: "It's official we don’t have a clue who’s who anymore.

"Sienna spent a whole day as Cosette, a simple clothes mixup and we were in trouble!"

He continued: "Lucky for a little mark from hospital on Sienna’s leg, otherwise we would have made the switcheroo."

Have you got any tricks for Sam on how he can tell them apart?