Did you ever regret not dating more people before you settled down?

My SO and I have been together since 15 years old been together for 10 years. We always have had a great relationship never broken up, never dealt with cheating or abuse. I’ve always feel so proud when people ask how long have you been together and they are always surprised at when we tell them how long. I’ve always been content with our relationship the only big issue we have ever had is his mom she would like to tell us that we need to have life experiences and be with other people or we will regret it one day. She would say this a lot even after 5, 8, 10 years of being together. This always hurt my feelings because it’s pretty much telling him go date and sleep with other women and cheat on your SO of 10 years. He never gave me a reason to believe he would do this and would always tell his mom I don’t need to I found the love of my life.

But somehow her words sunk into me and give me anxiety that if she tells him this enough he will feel the regret or lust to be with other because she try’s and drills it in our heads.

Does anyone else agree that it’s wrong for her to say this after we have been together for so many years?

Also anyone who got together with there SO at a young age did you ever feel regret to not have experiences dating many people?