Telling My Son About His Mom

I'm a single father of a four year old and he's had an on again off again relationship with his mother. I have full custody but have been lenient with letting her have him over her house based on the treatment of her mental health issues. Things were fine until she stopped asking to see him out of the blue, I inquired about her status and was told she was manic and off her meds and not in a state to see him and this only seemed to get worse.Now she's manipulating 3 different people with different versions of a story. She tells me she's anorexic and dying, she tells her mom she's moving to Arizona and she tells her father a combination of the two.So it's clear to me, right now, that she's lying to someone and I think it's me and our son and she wants us to believe she's going to be dead.He got used to going to see her every other weekend and now that it's abruptly stopped he is asking about her, I've only really been able to tell him she's sick and I don't think he could totally comprehend the tale she wants me to believe. So what do I tell him to get his mind off of her? via /r/Parenting http://ift.tt/2h9Y7Tp