i’ve had my bestfriend since 2nd grade and they have met other people they consider their bestfriend. We are now in college and i’m still their bestfriend and roommate when their other “bestfriend” goes to the same college as us. Their “bestfriend” is temporary, you will always be the A1 since day 1. Just don’t get jealous and let them live their life if you wanna keep them around.