Maybe if you act more mature and serious then they will follow .
If you look like you don't find it funny then maybe they will stop.
Sadly, there is nothing you can do. Your friend will have to mature at his own rate.
Tell them that you are very mature now and show them that you are mature.
Yes as long as all three of you can be mature about it.
She probably just wants to feel more mature. Ask your sister to give your friend the brush-off in the nicest possible way.
Always make time with your best friend. Don't be mean to the other best friend. You can be make your relationship suffer from your best friend. And if you feel like you aren't being wanted from your friend say to him/her about your feelings. BUT MAKE SURE THAT YOUR BEST FRIEND IS REALLY SUPPORTIVE
it depends, if she is single go for it and hope for the best.If your other best friend is her boyfriend than idk
Get marriage counsellor. Some mature common friend or relative is the next best.
Hang out with them for long periods of time, and always be there for them, they will be there for you and that's how they will be your best friend
The best way to make a friend is to be a friend.
It also depends on how mature your friend (or you) is being about it. If you are both mature about it, one of you will probably get her (assuming she likes one of you) and the friend who didn't get her will get over her and be happy for the one who did get her. If the level of maturity is low, then (still assuming she likes one of you) one of you will get her and the friend who didn't get her will be mad and make a huge deal about it.
Guy Code - 2011 Choosing Wine Acting Mature Keeping Your Distance from Your Best Friend's Girlfriend 3-8 was released on: USA: 6 March 2013
Hang out with them for long periods of time, and always be there for them, they will be there for you and that's how they will be your best friend