I (38F) decided to come out as poly to my sister (25F). She’s normally pretty open minded and is also pansexual so I figured she would be fairly if not totally accepting. Well, it backfired and she told me she was concerned about my marriage and afraid of how it’s going to affect her nephews and niece. When I asked if she would be willing to meet someone other than my husband that means a lot to me (hypothetically) in the future, she gave me a hard NO. Even after telling her that my husband (30M) and I are OK and we agreed to it, she only sees a negative outcome. I came away from the situation feeling shitty and disappointed. I want to bring this up to her again but really need advice on how to approach this.