first you ask them if they had to choose if they don't then watch her at all times and see how she looks at other people.
Chat with our AI personalities
No in fact it's totally normal, you have hormones and they can tell you to like someone and its ok to like your older brother's friend.
write a note to him and tell him to ask you out, but not in a mean way, in a nice way
if your friend can trust you, then say to her something like "i promise i wont tell, in fact, ill give you $50 if i do, and a REALLY don't want to do that." YOU PROBABLY WONT HAVE TO DO THAT UNLESS YOUR FRIEND IS SERIOUS, AND ISNT THAT BUBBLY (MAD/EXITED/FUNNY/HAPPY), BUT JUST ABOUT EVERY1 I KNOW CAN CAN OVER IT, JUST SAY TO THE GUY/GIRL "that was like, a year ago, and i definitely don't anymore..." hope this helps <3
Tell them they are
If I were in your position I would just stay friends with them you don't want to lose a best friend if you guys break up so I would just suggest being friends.