Very cute girl comes up on lane, and walks by me- smiles and says hello.

I was nervous but went ahead:

Me: Excuse me?

Her: Yes?

Me: Do you have a moment?

Her: Umm, why?

Me: I was wondering if I could introduce myself- I am ____.

Her: Ohh, ok...

Me: Are you in a rush?

Her: Yeah

Me: Too bad, take care.

I was nervous and couldn't smile properly- I came off as too serious - my voice was calm but I guess 'fun intent' was not present- I also dint move toward her. She seemed confused/surprised but polite- and I don't think girls go about smiling and saying hello to all the guys at stores.

Was it my approach since I dint smile and was visibly nervous?

Any advice on when girls react like this?