Oh yeah, I'm totally convinced that no lady has ever found it difficult, bordering on impossible, to take your 10".
Note that the "ideal" penis size cited by the vast majority of women falls somewhere near the 7-8 inches range, and you will be hard pressed to find anyone that would say less than 6 or more than 9 inches. So yes, obviously size does matter, and anyone who claims otherwise is either being dishonest or wouldn't know any better!
Fittingly though, the majority of these so-called "bulls" aren't any bigger than that, and the size thing appeals mainly to couples where the male falls well short of the acceptable size range. I'm guessing that's the kind of couples you meet and base your perception on, because I doubt you would be able to handle facing a guy who could actually provide any serious competition. For each of these crazy white boys who get their fix from being inadequate and sissified cuckolds, there's an equally detached from reality "bull" counterpart who himself is fundamentally nothing but an insecure boy seeking for ways to assert his supposed "dominance". And then there's others, like us, who just like to fuck around and have a good time without these autistic "superiority" and "submission" notions.