The Flopper . . .

[playfelt]

You mention the length of time. Address that with the idea that while you are there the other children are waiting and that isn't fair.

Option two is similar but tell them you are unable to stand at the door so unless he makes it go quick you will just have to leave to go back with the other children and he can send her in when she is ready.

Tell him enough is enough and he is to bring her to the door and kiss her goodbye and leave. You will assist her with her coat and boots. Then once parent has left. Leave child at door to take off her own things as she does after outside time. If she protests remind her that dad had to leave because SHE makes it too hard for him to come in. Take the coat and boots if you need to and let her pout her way to the playroom but make it all quick, matter of fact and do not engage in any conversation with her which will be her stalling tactic.