It basically means that if you don't want to give it to me then I don't want it. Too many stories I have heard about buds that have gfs but they have to make give them. (mine have always loved to give em !!)
If I think that I am putting you through something that you dont' really want to do just for my benefit then I would rather not waste my time.
on the other side of the spectrum the BEST ones are ALWAYS ALWAYS the ones where she looks like she having more fun then you