It's bad to date an old love interest's sibling.
Delia was dating Kevin for a long time, and they broke up but Delia sees Kevin's brother Dale at the bar and is asked out by him.
Delia wants to respond to Dale.
Delia tells Dale that she won't date him as she dated Kevin.
Delia tells Dale that she will date him.
Kevin will be able to live peacefully without his brother dating his ex.
Kevin will feel awkward whenever Delia is around with Dale.