Answer his question? You're not just going to stare at it ... Either say "yes" or "no". To be honest, this guy seems to be very "beg" - meaning desperate ... Um, he should not have just pulled out his penis and showed you it. I would have probably started to laugh if I was in your situation. Laughed because "normal" guys do not do that. He lacks maturity. Also, it shows a lack of respect on his level. Meaning, he wants to know if you like the size of his penis because probably if you said "yes", he would have thought "yah, she will put out for me". Very wrong on his part. Stay away from him because he just wants to get into your pants, as Jimbo37 said too.
Hmm. That's sick. As a guy, I would go ahead and kick him hard. If I were a woman, I would go ahead and kick him hard. He's either a really stupid joker, or he's hoping to get your attention to get "funky" with him in bed. Altogether, I'm assuming his "you know what" is his privates.
He sounds like a pervert. Stay away from him cuz he doesn't like you, he just wants to get in your pants. Make it obvious you want nothing to do with him. Sounds like a rapy guy. I don't think he realizes that that is illegal for him to do.