Answer and Explanation:
FATHER: I know, I know...
SHARON: You're the one who said I could go on the excursion, dad. You told me to do my chores and do well at school, and I did. I even got a B in Math, and you know how much I hate Math!
FATHER: Yes, son. I get it. You are right. But back then I didn't realize the dates would coincide. Don't you think your cousin will be disappointed? She loves you and has always supported you in everything. Don't you think you should support her at this important moment?
SHARON: Well, I hadn't really thought of that. I guess I would be hurt if she didn't come to my wedding to go on an excursion with her friends, if it were the other way around.
FATHER: Right? I know she is usually very understanding, but this is truly a unique event in her life. I can see you're putting yourself in her shoes already. What do you think is the right thing to do?
SHARON: I'll come to the wedding, of course. She has played a huge role in my life. Denying that would be very selfish of me.
Note: there are more than 100 words. Feel free to edit anything you see as unimportant to the dialog.