United Kingdom, March 6 -- Millie Bobby Brown played "hide and seek" on her 21st birthday.

The 'Electric State' star - who is married to Jake Bongiovi - celebrated her milestone age on 19 February and she and her pals had an amazing time embracing their "inner child".

She told 'Extra': "Yes, I had so much fun.

"It was a great 21st. It was amazing.

"I was with my girlfriends and my husband, and all of our friends were together, it was a big group of us.

"But we had the best time and basically just played hide and seek, and did all the things that your inner child wants to do.

"So, we were just able to hang out and have fun.

Millie stars in 'Electric State' with Chris Pratt and not only was she delighted to make a "genuine" friend, s...