My sister is going to be my date at my wedding

I (26M) am going to be married. I am a widower and I will be marrying my deceased wife’s sister, I was very close to both of them growing up, they were neighbours of mine. I was able to cope with my sister-in-law’s presence because she was the only person who understood me and the feelings I had about my deceased wife. <br><br>When I met my deceased wife we were kids, and she had a sister who was a couple years older but she’s always been very kind to me and very affectionate, so I was very close to both of them, and for that reason I feel very close to my soon to be second wife. <br><br>The problem is my sister 30F, she and I are very close and we have been neighbours since kids, exactly like my soon to be second wife, and she knows I am in love with her, she knows I’m going to break up with her if I were to get married.<br><br>We are a family like the Waltons, my 115 year old great grandma lives with us (me and our parents), my sister and her kids live with us too, my soon to be second wife lives with us too, my brother and his wife live 3 minutes away walking, my deceased wife’s and her sister’s parents live 2 houses away, my wife’s best friend is my sister’s best friend, my soon to be second wife’s best friend is my sister’s best friend too <br><br>I don’t know what to do because I don’t want to leave my soon to be second wife, I am very in love with her and I don’t want to break up with her, but I also don’t want to hurt my sister’s feelings. I am a family man and I love them all, and I don’t want to hurt my family.<br>I also don’t want my daughter or my sister’s kids to see me with my soon to be second wife because they are all very young (my daughter is 3, my sister’s kids are 5 & 6) and I fear that seeing me with my soon to be second wife in a wedding will give them the wrong idea of what marriage means and they are all very young. <br><br>But I also need a date for the wedding, my brother and best man is married, my best friend is married and he also has kids, and I can’t ask my sister-in-law because she’s my soon to be second wife and I don’t want my family to know. <br><br>So I am thinking about my sister, but I don’t want to hurt her feelings. What to do?