Walking with my Daughter-in-law

I walk with my Daughter-in-law every day to take my Granddaughter to and from school and we take their dog with us that they just got about 2 weeks ago. Well one day as we were walking to school there were 3 girls which I would say they were around 15 or 16 yrs old and they asked if they could pet the dog and we said sure they can. I told them that he was my Grandpuppy and the one girl said "you don't look that old, you look like you could be her husband" (LOL) referring to my Daughter-in-law. I said "Thank you, that made my day but that's my Daughter-in-law and my Granddaughter". I'm 49 and she is 29 and as we were walking away we were laughing about it and again I said "she really made my day" and she said "I wonder how old that girl thinks I am, in my 40's" and we both laughed it. That's like the 3rd person who thought my Daughter-in-law was my wife, the crossing guard thought she was my wife...LOL Now it's a little joke between us 😂