From my experience dealing with young people in schools, some people are different in different situations. They may clown around with friends but be staid with “authority” or any combination of things. They may seem sad or troubled because of a home situation, but that part of them does not come out with other people in other settings. People are complex.
I see no upside to informing anyone that so and so, “Is extremely insecure”. You can ruin it for him.
My 2 cents is to let the date decide if she sees that trait during dating, and if she does, does she even sees it as a negative?