Relationship advice please !

*edit- she doesn’t live with us, she lives with her parents as she’s at uni and can’t afford to move out and she has a boyfriend, she broke up with him because she said she didn’t love him anymore and they both agreed they had felt life friends for a long time.

I live with my boyfriend, we’ve been together for 5 months and I love him very much but he still speaks to his ex everyday.

So basically they coparent the dog they had together, she is at our house 4/5 times a week while we both work (she looks after the dog while he works) and I have been understanding because I want him and the dog to be happy. But i feel like I will never be good enough for him and that he will never love me like he did her. They were together for 6years, which I understand is a long time as I was with my ex for 5. But he still has photos of her all over his social media, which I have said upsets me as I don’t want to see old posts of him expressing his love for her and he has never posted me. He said that he has never deleted any of his exs of his social media as it’s just memories and he isn’t going to start now.

She says she can’t take the dog to where she lives as she lives with her parents and their dog so she has to be in our house everyday which I am not comfortable with, I mean she is a lovely person but still I don’t like it. She’s currently at uni and plans to move 3+ hours away next year for 3 years and they spoke about the idea of having the dog once a month each, she never has her in the evenings or nights so we never get time to ourselves but when she is away he can’t work so has to work around her.

And he is always sending her videos and photos (of the dog) but while we are spending time together when I asked for it to just be us and no phones.

I just feel really uncomfortable with everything, but I’m not sure if I’m overreacting because of my previous relationship or being delusional. Every weekend he is at work and I have to wait in all day for her to turn up to take out the dog and it is the worst day of the week for me and I don’t feel like I can relax or do whatever I want. I feel like he wants to hold on to her or something.

It just feels like we don’t have our own privacy because she’s included in our lives every single day. When I’ve brought all this up also he said that I knew about them competing the dog together and that she was in his life still but I didn’t realise how it would be. And when I said can you set boundaries with her he said it’s easier said than done?