We have been separated for 2 years and have a 4 year old son. We have an arrangement which works, 2 weekdays and alternate weekends. My family usually facilitate care on the Saturday day as he is working. In retaliation to me selling my house and him thinking he is entitled to something out of it (my mortgage, my deposit, my bank account, not married) he has now said he’s going for 50/50 and wants an offer from me out of the house. There is currently no problem with the current arrangement and he now has sent a very aggressive solicitors letter saying he wants to completely change it and if I don’t agree within a week he’s starting court proceedings. He is a pathological liar (undiagnosed) ex drug user and has let our son down on several occasions, he has tried to justify that he will be able to facilitate shared care because he new gf of a couple of months will care for him, im naturally not comfortable with this but will a court see this as reasonable? he lives in a touring caravan and often brings him home hungry and in dirty clothes which are often too small and doesn’t brush his teeth etc etc. I fear so much they are going to be taken in by his lies and believe that he can facilitate the care our son needs but I know he can’t! We are booked in for mediation but he’s already said he’s just going to say what he wants and that’s all he’s prepared to say! Help please any advice or anyone who has been in a similar situation? Thank you