I've been with dp for a year and knew him as a friend for over a decade. We were just friends for many years, met at an old job and stayed in contact as we work in complimentary fields and I would sometimes help with projects he was working on. It was 100% only friendship - I wasn't into him at all, had a relationship at the time and as far as I knew, they had a happy relationship and family.
Dp has a DD who's 7 and broke up with DDs mum 2 years ago . It was a very toxic relationship. She was controlling and has BPD so mentally unstable and can go absolutely crazy then calm down after a day or so. This isn't just DP saying this, I knew about this when they split up and before we became an item and have witness this over the year we've been together.
She never liked me throughout their relationship - she didn't like any woman that DP was friends with. Since they split up DP used to have their DD 50/50 but when she suspected he was seeing someone else she stopped him from seeing their DD for many months. She's suspected that me and him are together as during a handover she saw my name on his call list. He didn't confirm we were together but she stopped contact for a while due to this.
She's been snooping on my social media and companies house to try to figure out if we are together and has questioned many times about me. He hasn't confirmed as it would get her angry but has said many times that who he is seeing is none of her business and they are not together or ever getting back together.
She's now let him see DD again but I'm having to be kept a secret or she may flip out again and stop contact. I can't see their DD and have to ensure I'm not about just in case their DD sees me and mentions something to their mum.
For now I'm ok with this as DP is now able to see their DD and things are relatively smooth with them. I just want to ensure DP can see his DD. He has considered court to get an agreement in place but is worried she could move away or make malicious allegations against him - which she has done before.
Has anyone else been in this situation? Should he just be open with her that he is with me? I don't know how we can have a normal relationship like this. It's so dysfunctional. I feel like the other woman and everything revolves around making sure she doesn't flip out and stop contact.