I think this might have a lot do with your security of your relationship and with yourself. You keep mentioning all these "hot" girls are friending him for you and your friends to see. Are you not looking forward to the shit you will get from your friends and their outspoken opinions? They should know better than to really get on your case about things if everything else is going alright.
It reminds me of the time with my ex when she would see photos of me and a friend that was a girl that just takes millions and millions of pictures whenever you are out or around her. A lot of that had to do with the fact of how unhappy she was in the relationship and it further heightened it when her friends gave her shit for it. It made things worse all around and bred distrust, something that you don't need.
At the same time, I can understand from a privacy point of view that friending random people isn't cool especially with the repercussions you can get from schools or employers being able to view your private life.
I reject people I don't know all the time. I wouldn't say I get loads of hot girls doing it for me, but what is the point? For an ego boost?
Waking up next to a beautiful girl,
Step outside and say hello to my beautiful world.