Don't know if I'm getting worked up over nothing

So I'm a step mom, im married and my step son is 6. My husband and i have full custody of my step son and his mother sees him on every other weekend. (Dont want to air her dirty laundry but she had a bad history)My step son told me today that him and his mom were talking the last time they saw each other about how dad sleeps in sometimes, she called dad lazy and step son said no he's just stressed (lol cute) then his mom says well I love you and I love your dad at the end of the convo to end it. So problem is I am obviously extremely upset by this and idk what to do or feel. I have never met the mom and don't think I could without screaming at her. I am very protective of my husband as we were long distance for many years. Am I getting overly upset? My step son is only 6 so I'm possibly taking what has been said completely wrong and getting all worked up. If you read this long ty and please give me advice.