Concerning

My husband has two Boys before our marriage who I love to death. His ex had a child before they got together and he adores her and still has a pretty good relationship with his ex’s daughter. They were together for 13 years off and on. We’ve been together for 5 years and he still has pictures of his ex on his phone with the kids. It’s quite upsetting but his excuse is that he only keeps them cuz the kids are in the pictures. Do I have to irritated about it?