Why is Curly always looking for his wife and wear a boxing glove on his hand?

Curley doesn't trust his flirtacious wife, and Candy notes that Curley wears a left glove full of Vaseline to keep the hand soft for his wife, whom he thinks is a tart.

He is jealous and paranoid of other people seeing her, as there is a barn full of men and thinks that she would be with one of them and is insecure about it