I bet his brother is pissed.

Uhm... never thought of it that way.

But aren't twins pretty much only identical until puberty?
I mean sure, they must still be very similar, but it's very easy to tell them apart by their faces alone now so their bodies must be completely different as well. Two fully developed twins obviously still are very much alike but I seriously doubt they'd have the same body shape (since Coul has always been thinner), body hair (or the lack of it in their case), muscle mass, genitals lenght and shape... I'm not an expert though, so if anyone would like to correct me, go right ahead.
I just don't think Cole would really think of it that way. From what I've seen he just poked fun of Dylan for having a small member (indicating that his isnt identical?) on his twitter as well so he's not making a big deal out of it either.

I'm not an expert though, so if anyone would like to correct me, go right ahead. It literally depends on the twins... Genetics is complex and complicated, and epigenetics (the concept of outside factors like environment and diet influencing our genetics) is becoming an area of increased study, so all I can tell you is that is will certainly depend on the set of twins.

I'm not an expert on the Sprouse twins, so I don't exactly know what type of twins they are. If they are monozygotic (identical twins), then a single ovum was fertilized and subsequently split into two to make two separate, yet genetically identical, twins. If they are dizygotic (fraternal twins), then two separate ova were fertilized and subsequently implanted, and they are no more genetically similar than any two sibling. By appearance alone I would assume identical, but the Olsen Twins were often assumed to be identical while they are in fact, fraternal, so I'm not going to make assumptions.

There are a set of twins who are famous (or infamous depending on who you're talking to) who do gay, incest porn, called the Peters Twins. These two are literally identical. They have the exact same face, body, genitals, etc. Another set of twins masturbated together on a gay porn website SeanCody, and while similar looking with similar body types, one had a longer, thinner penis, while the other had a slightly shorter, girthier one. I understand that it's weird that I keep referencing twins in gay porn, but I'm gay and have seen these particular porn videos, and since you're inquiring about differences in genital size amongst twins, I found it to be relevant. So it's entirely possible the Sprouse Twins are the same in every way. However, it is equally possible that they are developed differently and have notably different. And then you put epigenetics into the equation, and who knows. It really is impossible to tell at this point.

But ultimately, I think he was just trying to insinuate that he and Dylan are bigger than the picture would suggest. I mean, it isn't like they are absurdly small (certainly not absurdly large, but not terribly small), but many guys are super self conscious about size.

Thank you, that was an interesting and educational read. I'll rather pass on those videos since it's not exactly my preference, but I still found it interesting. I can't help but wonder how it feels for them however, it has to kind of feel (and especially look) like you are having sex with yourself.

Genetics was always something I was interested in at school even though I did not fully understood some of it and we never really got to the genetics of twins unfortunately which I was curious about. I've heard people say that once there are twins in a family, it is bound to repeat a few generations later, or at least it has a significantly increased chance of happening. My greatgrandparents from my father's side had two identical twins aside from my grandfather and two other children, unfortunately one of them was born dead and the other one died shortly after, too. What do you think could be the likelyhood of me having twin-children, if any of what I heard is true?

It's tough to say and it depends on the type of twin. It's not true that identical twins run in families. And not much is known about what triggers a blastocyst to split into two separate fetuses; it is very much random. The only correlation found is that older women are more likely to have twins. Fraternal twins can run in families. A woman typically only releases one ovum per menstrual cycle (ovulation), however some women may release more than one (hyperovulation). The release of at least two ova is necessary for fraternal twinning. And it's this tendency towards hyperolvulation that can be genetic.