From all I've read on this site, I would be considered average, not small.
I'm 5.75" long, 6" on a very good day, and about 5.5" around. Not big, but not small but any scientific definition.
Yet, I have been called small and made fun of by a number of men and women.
First, a long time GF told me repeatedly I was small. She said her old boyfriend was as long soft as I was hard. I never saw him, I have no idea of his endowment, but it's entirely possible. Her comments were definitely designed to make fun of me.
Another girl, a friend with benefits, saw my cock for the first time and said,
"Is that it? Is that all you got?"
A male friend, who saw my cock, while having a threesome said, "you ain't got nuthin." He was definitely trying to diss me for one reason or another.
our friendship survived this idle, stray comment.
Another GF looked at my dick and said, "You have a small penis, but think of it this way, at least no woman will ever say it's too big."
So, remember, I'm 5.75 long 5.5 around, and I've got these comments from a number of partners. Probably some I'm forgetting.
My point is that people say shit. People don't always worry about saying the right thing. Yes, it's bad to make fun of people intentionally, but you cant' criminalize people for saying what they think.. Slightly thoughtless, insensitive people come out with things. I may be very average sized, when scientifically measured, but small in many people's minds.
We all have to be really secure about our sexuality and our bodies, because even if we are "ok" there will be people who will tell us we're not. We can't walk around sensitive to every stray insult flying around our heads or we'll never be able to deal with the important shit.