My friend, let's call her A, has a boy with, let's call him B.
B cheated on her for months, then dumped 2 weeks after proposing to her 
a few months ago. They have sort of agreed to split the care of their son. They each have him every other week end.
So far so good (although the split is far from amicable, as you can imagine, after all the arseholery he's put her through).
Anyway, they had verbally agreed to split the half term break in half. B would have the boy from today till Wednesday, and A would have him till next week.
Now B has changed his mind, said he had never agreed to that in the first place, that he's now taken a week off work, and that he will not bring the boy back on Wednesday as planned. He grinned and added that there was nothing she could do about it.
She doesn't even know if B is taking him away on holiday (not abroad as she has his passport I believe, but still).
Does she have any rights? What can she do? Is there any legal requirement that could force him to bring the boy back? I don't think there is any court order in place as to when they each have the boy. (poor thing 
).
She is devastated.