Personally, I'd never use the word 'incest' in an interview no matter the context. Keep all your words positive and focused to leave a good impression.
There are plenty of ways to say that you're eager to learn from others, make a change, experience new things, without mentioning that you weren't accepted elsewhere. Find an awesome strength about the program (even if overall it's not as good as the other one) and focus on that. Tell them that's why you're interested.