To preface, my ex is extremely awkward, and always has been. He still holds a huge grudge about me splitting up with him 6 years ago, and is very combative towards me. Despite me trying to have a civil relationship with him and co-parent DS (8) as best I can, he takes every opportunity to express his bitterness, be rude to me and generally make life difficult. I've moved on with a new DP, successful business and a new baby on the way, while he is still in the same position he was 6 years ago, which he constantly weaponises and expects sympathy for. He constantly brings up the past in conversations and things that happened years ago. This extends to him always attempting to avoid and do as little of his parental responsibilities as possible, including never having our DS overnight since we split up.
Due to his behaviour, he does not have a great relationship with DS. He only sees DS every other weekend and sporadically in the holidays, but never overnight at his own place. He doesn't have a suitable place to have DS because he has lived in house shares with random people since we split up. On his weekends, DS and him do the same routine, and often end up spending hours sat in his car as my ex does not want to spend the money on day trips and again, doesn't have a suitable home environment to take DS. He's also very strict with DS, and doesn't understand his struggles with ASD and ADHD (despite me explaining them) so he constantly tells him to 'make eye contact and look at him' and belittles him for not being able to listen and follow instructions well. All in all, DS doesn't like his dad, expresses this often and says every weekend that he doesn't want to see him.
Last night, ex-DP announced he would be having DS overnight from October as he would be moving out of his house share and in with a friend. I asked who this friend was, and he said it was a woman called 'Anna'. I know of Anna, he met her on Tinder and had previously told me about dating her. I asked if that meant Anna was his girlfriend, to which he went on a texting rant about how I have no right to know if it is romantic or not, and I have double standards as I have introduced DS to ex partners, and essentially he did what he always does which is bring up things from years ago. I told him that I don't care who he is dating, all I care about are things that impact on DS, and as DS has never met Anna before, actually it is pertinent information if ex-DP is moving in with his girlfriend that DS has never met or heard about and they are expecting to launch DS straight into overnight stays with them both. I told him it's inappropriate for DS to be staying overnight frequently with someone he has never met, doesn't know, has never heard about and yes it makes a difference whether they are romantically involved or not (only from the perspective of DS, who I know will be confused and uncomfortable in this situation). I do not feel comfortable with DS staying overnight, given these circumstances, and the attitude of my ex-DP.
This morning I've had a huge text message paragraph about how unreasonable I am, being incredibly rude to me, and again bringing up things from years ago. AIBU to think I have a right to know this sort of information, in these circumstances, and my ex-DP is just once again being an idiot?