Why ask her about past dicks?
It seems like you can read threads forever on this site and barely make a dent at the sum total of information that has been contributed. I read all kinds of threads and can be found in almost any forum as this site has much more to offer than just penis exercises.
The only thing that surprises me is how many dudes are discussing with their women the sizes of cock they have had previously?? I know the subject may come up, but it seems much more common than I thought. I understand the gratification that may accompany your lady telling you that you are by far the largest thing she has ever experienced, but how likely is that?
My girlfriend has only made references to the fact that sex feels tight and that she doesn’t want anything larger (although I could care less about that request). We have never talked about past lovers nor do I want to go there? It just seems like a surefire way to develop issues between the both of you (more so than a positive outcome; i.e.: “Baby, not so deep, you’re punching my spleen”).