Who's Married to Whom?

Four married couples belong to a club. The hostess posed this puzzle at the first meeting so that the members could figure out who was married to whom. She gave these clues to the group:

The wives' names are Linda, Lisa, Glenda, and Dee.

The husbands' names are Tom, Duane, Ron, and Ernie.

Ernie is Glenda's brother.

Glenda and Duane were once engaged, but "broke up" when Duane met his present wife.

Dee has two brothers, but her husband is an only child.

Linda is married to Ron.

So, who is married to whom?