Kristen Bell has unveiled a song her three-year-old daughter Delta wrote about farting.

The 38-year-old actress - who has daughters Delta and five-year-old Lincoln with husband Dax Shepard - shared a video of herself singing the song which she recorded with her best friend Bob Mervak titled 'Oopsies' and added that her pal Bob was ''pure magic''.

In an Instagram video posted on Thursday (21.03.19) she said: ''My best friend @bobmervak is pure magic. This gem started as a little tune he created with my 3 year old daughter in our living room and has now grown into a full symphonic masterpiece.

''I am in constant awe of his gift and feel so lucky to know this walking reminder of the power of music. Recording this was some of the most fun I've had as a grown up. This delight is now available for your on iTunes, Spotify, YouTube, anywhere you get your music. (sic)''

The 'Good Place' star is a sharer when it comes to her life as a parent and recently revealed that she and Dax gave Lincoln the ''birds and the bees'' talk after she asked how babies were born.

Appearing as a couple on 'The Ellen DeGeneres Show' they revealed that Lincoln grew ''bored'' after her parents attempted to explain the functions of the reproductive system to her.

Dax said: ''We didn't like, 'Oh crap, got to get around to that talk.' ''

Kristen added: ''She said, 'Well, where do babies come from?' And we were both like, 'OK.' ''

Dax continued: ''We went through the anatomy. Penis, vagina, ovum, sperm. We were laying it all out. But when it got to the actual nuts and bolts of the operation...''

Kristen then interrupted her husband, concluding: ''We bored her to death!''