Fiance calling children’s father daddy

Relationship Questions and AdviceCategory: QuestionsFiance calling children’s father daddy
Dylan asked 10 months ago

Been with my fiance for the last 4 years. She has two kids with her ex. Back round about him he’s been in and out of jail most of the childrens lives. Her and the children talk to on the phone ever once and a while. I heard them saying bye today, and I overheard my fiance say bye daddy to him. Should I be concerned ,or be upset/mad?