Help

Story goes i am a '28F' engaged to '41M',over a year together. Of course he has had partners before as have I. I never had an issue with him continuing friendships with said other partners until boundaries were crossed. One sent a message saying "I miss you"('F46') only together for a short period of time due to her ending things. the other one said ('F45?') "think about you all the time, miss you some". They had been friends as he said for YEARS. Never actually had a relationship. As we have both been cheated on in the past I felt this crossed a boundary seeing as they both (F that he has had sex with) knew he was engaged. We only had one big blow out about one of the females at the time. He then deactivated his Facebook account after both were blocked from Facebook and cellphone. He then made another Facebook and since has added both back to said Facebook. At first it was only one I made a fuss blocked her then a few days later I saw that he was friends with the other. I did not make a big fuss of it as I am honestly just so exhausted with trying to be understood. I told myself if he wants someone else so be it. BUT it has ate at me for days now so I finally said something and he said well to solve it we can both delete our Facebook. So here I am deciding if I end the relationship. There is way more to the relationship but this is already long. I apologize and any advice is appreciated. I dont know what to do, anyone have advice. Helllpppp??