I say.....
Just RELAX and get comfortable being around this girl. Have her do some ultra heavy foreplay on you. Tell ehr that no girl has been able to get you hard. Sh'ell love the challenge. I GUARANTEE that if you clear you mind, and relax, and concentrate on nothing but you and her, and let her lpay with your dick for a while, it'll pop right up. Remember, relaxation and foreplay.