I don't know where to begin, but here goes.
I have been with DS dad for 8 years, and we 6 year old DS. We both had DS young, I was 16, he was 17.
When DS was born, our relationship became very intense and toxic, and I suffered physical and emotional abuse from his dad. Luckily DS dad hasn't been abusive towards me for a couple of years now.
I got pregnant again recently and I lost my baby 
(I had an abortion, but it's still a loss, I was scared and I didn't want to bring another child in our fucked up relationship, looking back I wished I kept my pregnancy and ran away from the dad), I find it so difficult when I see many pregnant people with that pregnancy transport badge, many of my close friends have announced their pregnancies, and I feel utter shit, anyway that's for a different thread topic.
Even since the abortion, I haven't had sex with DP/DS dad for about....5 months now. DS dad and I have never lived together, only because I fear that the physical abuse will crop up again and I don't want DS to grown up in an abusive household. But every time DS dad/ DP calls me, it would start off as.." Hows, DS and I.." Followed by.." Can you come over to mine (basically for sex) ", when I tell him "no", he gets very angry and upset over the phone. Though to bed honest Mumsnetters, this has always been the case, he would always call me up for sex, or when he needs something; I tell him that "why can't he take me out", he is jobless and uses this as an excuse not to take me anywhere, but even a stroll around the park, a city, or even going to a free museum will be nice.
Another thing, every time he takes DS out (which is once in a blue moon if I'm lucky!) he always has the nerve to insult me when it comes to DS. As an example, he took DS and complained that the jacket DS was wearing was very dirty, that I need to clean it and he doesn't want no child of his to walk around looking like shit basically and in another scenario ( DS has quite bad eczema) DP/DS dad was questioning when I took DS to the doctors about his eczema, that his eczema is getting bad and that I'm not doing anything about it. I told him that I take DS to the doctor numerous of times! Also, that he went to specialist and the specialist concluded that DS has food allergies and this was making his eczema worse. But DS dad kept ranting and raving, that I keep listening to the doctors and that I need to use my initiative and that it must be the washing soap that I'm using which is causing his eczema to get worse etc etc.
Anyway two days ago, DS dad asked me to come over to his- again, and I just basically told him no that I feel like all these years our relationship has been based around sex etc and that he hasn't been consistent into building a relationship with DS. I feel like it's my fault, no sex for 5 months is a lot, but I feel like I shouldn't owe him sex after the way he treats me, and I can't bring myself too since the abortion. I feel like leaving him, I really do, I just want get away from him, but I don't know if I'll be doing the right thing.