My (26M) fiancé (25F) doesn’t want my murdered ex girlfriends parents at our wedding

The title almost says it all. I dated someone for 3 years, were decently serious (talked about marriage and post college plans), but we took a break (in which she sent me some photos she shouldn’t have) and we didn’t get back together. I didn’t talk to her after giving her all her shit back and about a year later she was kidnapped and murdered. It made national news and was a highly stressful time for me in which her father was my greatest ally and my rock. We formed a very intimate and close friendship (we had a great relationship while me and his daughter were dating anyway.) From media interviews to service ideas and insurance checks he was my guide and my rock. He and his wife have always supported me and encouraged me, even after her murder. I can’t imagine not having people who were so important to me during one of the darkest periods of my life at my wedding. I visited them a couple months ago and told them about my fiancé and they told me they couldn’t wait to meet her and how important it was that I moved on. I should also divulge that I was dating my current fiancé before I dated my ex, and left her due to distance for college, then quickly began dating my ex. So in my fiancé’s mind I left her to date my ex. She has been as supportive as she emotionally can be while watching me grieve the murder of a girl I once left her for. My ex and I’d relationship wasn’t going to be rekindled, and I wasn’t in love with her. I regret the way we left because she seemed to spiral after our final fight and made very risky decisions. So I have a lot of guilt about that but I’m trying to move on without completely forgetting her, she mattered/matters to me. I’m asking my fiancé to support me through her murder trial. Am I asking too much to have her parents at my wedding? They mean so much to me.

TL;DR Formed a supportive relationship with my ex’s father after she was murdered and we had to deal with the aftermath. Fiancé doesn’t want them at my wedding.