You should say no.
You shouldn't pretend to date her so she can piss off her parents.
You definitely shouldn't agree to take her virginity and show her all the experiences she's been missing out on.
And you really shouldn't keep it a secret from her brother, the one who's your best friend and business partner.
But I don't always make the best choices. In fact, I can be kind of a dick sometimes.
And I know if I don't do it, someone else will . . . and I can't have that. If anything, it means I get to be the good guy for once.
I just wasn't prepared for how gifted this good girl would be at going bad.