It's Okay! She's My Stepdaughter 5

This is probably the toughest decision of your life... Your stepdaughter is so fucking cute and you've actually masturbated thinking about her. Now, out of nowhere, she's hitting on you and makes it clear that she wants to fuck you!! Now what do you do?! Well, she's over 18, so that's not a problem. Hmmm, what do you do?