Opinion?

I reccently started writing this new story. I would like some opinions, if you don't mind. Thanks :D

Here's the background of it. Statistically speaking, twins tend to have their first sexual encounter with each other. They trust the other person and spending loads of time together doesn't help matters. (Remember this is statistically speaking, I'm not assuming that every twin does this.) Now, I'm writing a story about two fraternal twins (male and female) and they are lovers. They have friends, live normal lives, but hardly ever date. When they do date it's to keep up appearances for their family and friends. Their older brother is slowly catching on to what the couple is really doing.

So would anyone be interested in this story? Of how and if they will keep their dirty secret.