It had better be an honest excuse for not keeping the date. Have to study for an exam; you're grounded (and are); your parents want you home because relatives are coming over; a special occasion with family; you're sick, Bad excuses are: You want to go out with some of your male friends; you just don't feel like going out, etc. Phone her and be honest and if she is mature she's be able to accept it. You should always, if possible give her time to make other arrangements for herself. Being sick can't be helped, but other excuses are just not acceptable.
Answer
Depending on circumstances, you might be better not to phrase it as cancelling the date but instead as rescheduling. "Is it ok if we see the movie on Saturday instead of Friday?" Still a little bit awkward, but not as bad as cancelling altogether.
Get closer yea that happened on my 2nd date sorry
no because then your girlfriend would be cheating on you with your friend and you will be mad
never
If you're fighting with your girlfriend and you're not totally broken up you should never date anyone else as it's considered cheating; if you don't like your girlfriend anymore break up with her for good and then you could date other girls, but I recommend you don't if you're on a break (head space) with your girlfriend.
It is not so much the fact that it would be weird if you date a young man that thinks your brother's girlfriend should have been his girlfriend, but be more worried about the fact he wants to date you to be close to your brother's girlfriend so be smart and don't let this young man use you and cause not only problems for your brother and his girlfriend, but also getting hurt yourself.
I dont think you should.
ASAP
If he invites his girlfriend to homecoming, you should probably your own date to homecoming.
You should just ignore them and date someone else better then her or him.
It means to cancel a date or an appointment or a game.
It means he has poor morals and no integrity. Date him at your own risk.
You should get to know her and see if you still like her and if you do, then you should ask her on a date before someone else does.