Well there can be 2 possible reactions from her:
1) She'll play along with you and ask more about it.
2) She'll say you are too cheeky, thinking about such things.
Like i said again, you can never tell what they thinking. Best is
to rephrase the things you want to say, so you don;t give her the
wrong idea. Always play defensive, especially with a girl, even if
its ur gf. I got my fair share of arguements from not doing so in
the past. 
