These kids have grown up in a society where perverts, serial killers, rapists, and kidnappers are in the news almost every day. You do not know these people you are going on dates with. The kids are aware of this. Many women simply go on a date with someone and are never heard from again. They are right to be worried about you in these times.
They truly sound like smart kids that have been taught to be super careful when they're around someone they don't know very well.
I agree they are overdoing it though. They are just worried about you it seems.
I find it truly sad in these days that the first thing that comes to mind when a child turns 18 that they are living with their parents rent free. I think kids should not have to turn 18 and have to go find a job so they can pay rent.
I assume they are in school. If they are going to college in the fall they need to be planning on going to school and getting stuff ready for that. They don't really have a good reference for a job when they are leaving in a few weeks to go to school. They might have been able to find a job at the beginning of summer but now summer jobs are scarce. If they are not going to go to school and continue their education they need to perhaps start deciding what they want to do for the next few years until they realize they won't be able to make a livable wage without a college degree.
This child is legally an adult. They should be able to come and go as they please. They should be able to live as if they are an adult. Seriously. Think about this.
You have a person who is stretching their wings for the very first time. You can be there for them when they fail, because they always do. Then they look at you and think, wow, she told me all about this and she was right.....win win win.
They need you to allow them to make mistakes while they are still living at home and you have some influence, they'll come to you when they need help. This is a time for learning, they learn what being an adult is about in the next couple of years. Living at home but having a lot of freedom is good. They see what adulthood is all about and find they are not so good at it.
Having a young adult who is learning by making mistake after mistake after mistake is a great time for you to teach them by letting them make those mistakes that are not life changing. If you know they are about to go stand on the roof of a car and do road surfing, then you know you have to stop that with every available resource you have. They usually die from that. If they are going to a friends house to hang out and are going to stay until they get ready to come home....well, that's not anything worth arguing over.
You can choose how you want them to see you at this point. You can be the mom that says I love you, have fun, please try to be home before 2 so I can know you're safe.
Or you can be the mom they see as a bossy "B" they find they are at odds with and don't want to be around anymore, much less respect enough to go to them when they realize they are in over their heads in the general thing called life.
So try to lighten up, let them be an adult with a safety net, YOU. You have the best opportunity to be their rock when they need someone that is totally on their side.