Honestly, I'd think that most girls would be quite happy with the thought that they can turn their boyfriend on like that. I know most guys would definitely consider the opposite a good thing. Honestly, don't sweat it, even if she notices she'll probably just shrug it off, and that's if she doesn't actually like it; which she probably does.
All in all, the moral is: don't hold back when you hug your girlfriend. Life's too short for nonsense like that.
The atoms that make up you and me were born in the hearts of suns many times greater than ours, and in time our atoms will once again reside amongst the stars. Life is but an idle dalliance of the cosmos, frail, and soon forgotten. We have been set adrift in an ocean whose tides we are only beginning to comprehend and with that maturity has come the realization that we are, at least for now, alone. In that loneliness, it falls to us to shine as brightly as the stars from which we came.