Would you accept a diamond that has been worn by your SO ex fiancé ?

My SO asked me if I would mind if he used the diamond from his last engagement on mine... it was really expensive and it’s so big and preety but I don’t think I can get over the fact that it was specifically picked for his ex lol.. I know we can save the money for the wedding but on another note I believe certain objects carry a story and I don’t want to think about that everytime I looked at my ring lol plus I want a pear shaped ring and that one is a princess cut! Am I being selfish??