I'm tall and the guy I'm seeing is very tall. I'm 5'9.5" and I feel like I have to wear heels so he's not reaching so far down to kiss me.
Odd thing about your question is that that very thing happened to me the other night - I could feel his erection against my ass on the dance floor. I enjoy it somewhat, b/c it's reassuring to me that he's aroused when he's with me. Whether he was uncomfortable b/c it would be obvious or rubbing against his zipper, etc. I don't know.
An off-shoot of your question, I have a question in return - do you get embarrassed when you get aroused on the dance floor?