My friend and I have been planning to go out this sat and sun. I was looking forward to do it but I don't want to now and also I have a job interview to go to. I feel so bad because she really wanted to go out and she didn't want to go by herself. I feel I can't tell her now because she might convince me to go like she's been nagging me to hang out with her this weekend.
I was thinking what Stuff stuff was saying. Perhaps you could just say your busy with something, or you could promise/say that you could get together next time (soon). Yeah, this is pretty much what Stuff stuff said, but oh well.
If she is your close friend, i think you can talk to her directly, as an interview is more important. You can go out with her another time. i think she will understand you.
Well, just tell her the interview is very important, and you wont have the time this weekend, maybe another. Good Luck!