Sharing location with new beau

Do you mean the Apple Family Sharing group?

You control who has access to your location. When you consent to share you location it does not include that of all your contacts with whom you are also sharing. They have not given permission for their location to be shared, except with you.

To give you an example - my daughter and I share our locations; I can see where she is and she can see where I am. She also shares her location with some of her friends. I do not see her friends in my Find My app.

This is the case if you have separate Apple Accounts. However, if you use the SAME Apple Account as another person (a parent, for example), then yes, any device using that Apple Account will see the same location data.

With Family Sharing what you do remains private to you except where is it something specifically shared with others by you, or is part of a group of things that are shared such as subscriptions or purchases. Even purchases you can hide and prevent others from seeing them.