my stepsis' fiance

Daemon and you were lovers since college but your family doesn't know it. After graduating, you decided to work abroad. Your relationship is good at first but after 3 years you become too busy and ignore him. He loves you so much but you're too focused in your carrer and 5 months before coming back from abroad you lost communication.When you arrived home your father throw a welcome party and among the guest you saw a very familiar face, it was your boyfriend Daemon. Your pregnant stepsister noticed you looking at him so she introduced him to you and mentioned that he's her fiance. Will you keep your relationship a secret for the sake of family or will you get mad at him???