My girlfriend just asked me to do WHAT?

You tell her yes or no depending on what you are comfortable with. If you are okay with the idea then say yes. If you are unsure,upset, or offended you say no. I am not too familiar with how works. (I don't know if they use strap ons or not) I just find it odd that if you are a you would want a strap on. But like I said, I am unfamiliar with it and to each their own. Good luck! Stay true to yourself. Only do it if you are comfortable with it!