I took my kids on holiday a couple of weeks ago travelling from Birmingham airport. DP was travelling separately a couple of days later.
I got challenged at airport security: how do we know that's your child? Well, I have his passport and he shares my name. Not sure what else they were expecting?
Then stopped again at the gate! They took away DS passport, came back about 20 min later and gave it back to me. No reasons given.
Then on the plane, more oddness. One of the crew came over, checked that my child was with me (?) then phoned someone and confirmed we were together.
I found the whole experience mysterious. And they were only interested in my son (1 yo), not my daughter (3).