I like the childishness (but I realise you get that) in the characters but maybe change some of the dialogue.
I like the phonecall scene but I would suggest a slight amend - i.e.:
"uuurgh, it's a gyuurrrl for yuuuu!"; then
"oh, I've got to go ..."; and
no reason why.
On to the end..... in a similar manner as you have now... in the park with the baby, etc. but then the full reveal here as to why he got off!
Beef up comic moments too but I can't fault the idea.