Should I love you to be Happy?

Answer 1

You should be glad to see other people happy. That's normal. But what if the other person is only happy when he/she is doing something self-destructive, like drinking, drugs, gambling, etc.? There's nothing fun about seeing your friends go down the tubes.
Or maybe you are asking " Should I love it when my friend is happier with someone else?" That's hard to do too, but it will bring you more peace than being mad when someone likes someone else more.
But if you are asking if your happiness should be dependent on whether or not you love someone, I would say no. It's better when your happiness is not dependent on anything else.
Regardless of what it is you are asking, you are sure to have both a deeper happiness and greater sadnesses when you open your heart to love. That's just the way it works.