As much as we'd like the people we love to also love one another, that's not always the case. Whether it's a personality clash, jealousy, or another emotional reason, the simple truth is that not everyone can get along. It's an especially heartbreaking situation when your spouse-to-be despises one of your bridesmaids. Here's what you may want to do.
Find out why he dislikes her.
You had no intention of adding "peacemaker" to your already crowded list of titles (wedding planner, budget director, bridesmaids' supervisor, etc.) but this is too important to ignore. Be straightforward and ask your partner what the problem is. Did they have an argument? Was it about you? How justified is he in his animosity toward her? He should be able to discuss what's bothering him with you.
Be ready to accept that he may never change his mind.
If he's adamant about his negative feelings towards her—and she feels the same about him—don't expect them to ever be besties. You may have to settle on "civil to one another."
Don't un-invite her to be a bridesmaid.
Once you've asked someone to be in your wedding party, you shouldn't rescind the offer; that would be rude since she already accepted. But if you knew how he felt before you asked her, why did you ask her? Relationships are complicated, so maybe you felt obligated and were hoping for a ceasefire. The best you can hope for is that they stay away from one another in social situations, especially at the wedding.