Do they or is it different size?

What does D mean?

Ask them and find out.

I saw the title change

Nope

Yahoo! Answers will solve your doubt.

The title change.

Yes.

huh

edit: that title change it's too late

Fraternal (Identical Twins) most likely since they are genetically identical

Non fraternal no

Title change

Sometimes.

what? Same D size in relation to non twinks? probably who knows.

Ya'll are so quick for that report thread button

question 1: r u hot, r u a twin? i'll find out and tell u if your twin if as long as your twin is at least bisexual

Everyone does

The answer to both the current an old title is yes, they'd be very similar in size in most circumstances. Only wildly different diet, health etc could make identical twins extremely different from one another in this regard. Genes are powerful stuff.