My sons third birthday started off with him being at home in the morning. He doesn't like hearing either myself or his mum on the phone to him so I just waited to see him in the afternoon. But his mum text my accusing me of being a twat and not ringing him. If he was older I would understand but I didn't think it overly necessary when I was picking him up and having him overnight. But I rang straight away and he got upset and refused to talk to me and wouldn't say goodbye. I think my ex had a point but my son proved me right in being annoyed. It just made me feel guilty and shitty twice. 
My little boy got lots of good stuff for his birthday. 
My ex tried to grump further with me but I didn't know what the problem was really so I just tried to be polite. She sped off. You can't do right by your exs so it's not worth even thinking about. I do try to do everything right but then the other person will choose for you to have done something wrong. When all is said and done we barely say a crossed word so I can't really complain. My strongest ammunition is my indifference, I learnt that from my dad. 
Today I held in my hands an iPod 2. It felt at home. I felt happy. But I can't afford one yet. It will wait won't it. There are more important things to spend money on....although none spring to mind.