Thanks for advice. DS is ten months. Ex has had very little involvement throughout his life, refusing to spend time with him, do any of the things that help to establish a relationship - bath, bed, reading etc.
He broke up with me when DS was six months old, and made us leave our house. Since then I've been staying with my parents whilst I save for deposit to buy.
Ex now wants 50/50 split, on the basis that his brother in law has a 4 year old who spends half his time with each. The circumstances are completely different. For a start, I'm still breastfeeding, ex is living in shared house, and he hasn't got enough experience to look after him half the time, having minimal contact with him the last year. He knows nothing of his bedtime, how to sooth etc.
I've said I will consider overnights when DS is older and can understand what's happening and when ex has his own place, and it must be built up, not just going from 3 hours per week to overnights.
Ex makes threats about court action, and in the past few weeks the tone of his messages have changed from aggressive and bitter to very placid and reasonable sounding which I can only assume is for the benefit of any future case