I'm 39, DP (well, now ex) is 33.
Around 6 months ago a woman aged 51 got in touch with him to offer her friendship. She works for his dad's company and apparently his dad had told her my DP didn't have many friends in the city we live in and was worried he was suffering from depression.
She started to invite him out for coffee, weekly walks or to go to her house for Sunday dinner. Occasionally, her daughters were there but mostly not. She also asked him regularly to do odd jobs for her which he obliged. Apparently, she knows all about me and he talks about me to her (including details of our relationship which I think are private) yet not once have I been invited along. I have never met her.
About 6 weeks into this 'friendship' it emerged that she is in the process of going through a divorce. I just found the whole thing totally inappropriate and disrespectful to me even though he assures me he doesn't fancy her and doesn't know why I have a problem with it. It made me so angry but he continued to see her anyway. He never agreed to go on a walk when I asked him as said he couldn't be bothered. She is also attractive and I admit this made me insecure. I also to my shame admit to checking their messages on his phone but nothing incriminating except for XXX after all her messages. He didn't reciprocate with that.
The last straw came a few days ago. He knew Wednesday was my day off and I wanted us to spend the day together. Yet, he messaged her to ask her if she wanted to do something as said his dad would be annoyed if he didn't make more of an effort with her as he had been the one to suggest the friendship. She wrote back to my DP and asked if he wanted a walk and then dinner and he just agreed without even talking to me. I lost the plot at this stage and he said he didn't care and if I didn't like it I knew where the door was. I packed up my stuff and left.
My question is do you think I was justified in not putting up with this or have I let the green-eyed monster get the better of me? I have been to pick up the rest of my things since then and he did meet her in the end and I suspect one more time after that. I can't stop thinking about them together but wonder if I was just being crazy trying to stop the friendship, weird as I believe it is. Opinions would be greatly appreciated.