This photo of Ryan Reynolds has made some Mums quite mad. Can you guess why?

It's tough being a celebrity parent. Money, fame, mansions and night nurses aside, thanks to social media the whole world is watching as you take your first clumsy steps into parenthood. Take Ryan Reynolds for example. There he was, enjoying a day out in nature with his baby daughter James and gorgeous wife, Blake Lively. Later, Blake posted this adorable picture (complete with hilarious caption) to her Instagram account...

Happy Fathers Day!!! ... @vancityreynolds Since the day our baby was born, I've felt so strongly in my heart that you were most likely the father. ?????????#ILoveYouSoMuchItsSilly

A photo posted by Blake Lively (@blakelively) on Jun 21, 2015 at 7:29am PDT

Suddenly, the Mummy Mafia turned out in force. Why? Because of the way Ryan is wearing his sling. kelsey201087 says: "The carrier is used incorrectly. These types of carriers do not have the between the legs support so baby could actually slip through. This kind of carriers is an ergonomically supportive carrier and baby's legs should be frogged, or in a sitting position." Fan meagturn5 added: "It is dangerous to carry baby James this way, also it can cause hip problems," Adding a dash of realism to the discussion, buzzybree23 said she found it disheartening that people were so critical: "I am not a perfect parent-but I am a mother of 4- and so far- they are just fine... I am sure he is aware of whether or not she can breathe. I see a picture of a loving father spending time with his baby. #cmonpeople." According to experts, anyone concerned about hip dysplasia should carry their baby in the "M" position (bottom down and knees up).