My Dad refers to my stepmom as my mom and I don’t like it.

My parents divorced when I was 3, and my dad married my stepmom when I was 5. I’m now 13. My dad always refers to my stepmom as my mom and it makes feel uncomfortable. For example, he always says, “Go tell your mom I’m upset with you!” “You make me proud as your dad, and your mom feels the same way!” “What did your mom say about this?” What should I do? Should I tell him to stop saying that? I feel like he thinks she’s my real mom but she’s not.