I don’t think you should introduce yourself and ask if he wants to be friends — because the truth is, you don’t want to be friends. You want to date him, so stay out of the friend zone. 😉 I think you should flirt with him. Compliment him. Start a conversation. And don’t worry about the other guy. Rejection is just part of dating, and if you don’t try, you’ll never know, in addition to which, you never really went out with him, so there’s not a big deal involved in flirting with his friend. Don’t forget, he may be shy or unused to women approaching him, so don’t think too much about his not smiling back at you — I think you just took him off guard, that’s all. Keep going! 😎