Girls! I need advice. We're happy with my husband, but his sister keep…

Girls! I need advice. We're happy with my husband, but his sister keeps putting roadblocks in our way. She constantly stirs up trouble by reminding him of his past relationships. She calls him over for visits, and there are girls hanging all over him. We haven't spoken in a month (by the way, at her initiative), I lived this month like in a fairy tale. Yesterday she called him "missed you" and told how she lives. Then in the evening she called and invited him over (we didn't go). Our wedding is coming soon. I don't want to see her there, but I see how he's suffering. I decided to send her a photo of his invitation, which resulted