First, a toast to the man's grandparents, wishing the elderly good health (called grandparents), and then a toast to the man's parents (called uncles and aunts). Besides wishing them good health, you can say: My sister and I have had a good relationship since childhood. This time, my sister is far from home, and I am very sad. I hope my uncles and aunts will take care of my sister more in the future. Then propose a toast to my sister's boyfriend: I'll leave my sister to you. I believe you will be good to my sister in the future. I wish you happiness.