Invite him to join in

Truthfully, you've always lusted after your father, always wanted to see that big dick of his up close. Licking your bottom lip. You grin and gasp, still finger fucking yourself while you plead. "Mmmm, Daddy, I need a little help over here."

Your father looks stunned, to say the least, and his cock is so hard that it's now peaking out of his boxers. Lifting up your hips, you spread your pussy lips so he can see you rub your own juices along your clit.