It doesn't nec. follow that if she likes big penises, she doesn't like yours. If you go through with this, it could confirm that she likes yours better than a huge one. That would cement your confidence. This is what happened with my wife and me when we did some experimenting. In fact, her worst sexual experience was with a horse dicked dude. More likely, though, if you are there and can maintain the right state of mind, you'll both enjoy it. Just keep it in perspective, TALK with her at length about it. What she anticipates if you do it, how you will fit in, whether she would stop if you felt too hurt, couldn't handle it.