A lot of people say/write : Sweetheart=darling=honey . It is an affectionate way of starting a sentence or greeting. Example: Sweetheart how are you today? However a lot of husbands reply "yes sweetheart" in a sarcastic tone when their wives ask them to do something at home.

Older men also use it as a term of endearment for younger girls. おじいさん言葉だね。

”恋人”の意味があります。。彼はあなたに口説いたいそうです。。気をつけてね

sweetheart = darling