I love photography and have done since I was a kid. During your session, I always tell clients it totally fine to take behind the scene photos. Why? because this is a special moment and you want to remember it. Some photographers don't like you taking images but the difference between the final image I take with my training and experience vs your iPhone pic over my shoulder is very different. My only request to clients is they send me the behind the scene shots.
Here are some samples from the past year.