Responses
It's not about the size, but how you use them. The massive size are always just to emphasize the extraordinary quality of a seme. Couples who have roughly the same build usually just have noticeable difference of size but not that huge.
Average or just above it are more than enough to make them moan. (づ￣ ³￣)づ
I've read so many yaoi where the uke is like "that won't fit in me" and I look at those white blurs that are bigger then the uke's head and think "really, that's gotta be exaggerated". But, I don't really want the spam that would come from Google searching "how big is an average p*nis?" Now I know and now I know that a requirement for a great seme is a massive p*nis