Mandyloo, it's seems harsh but I think it is better for your son that his dad isn't in contact, it's better that way than hit or mis, touch and goes that my sons are experiencing.

My lads get upset that the contact is just around events, because they feel that their dad contacts them to make himself feel better more than really wanting to be with them, I have to say I agree.

That is a family thing on the in laws side, must visit birthdays, christmas, before a holiday, after a holiday, but never in between these times, so maybe, even though H thought this was crazy, he is falling into his families bizarre ways.
I don't know, it's just not worth worrying about.