NO THIS IS NOT VALID! "Dreamsexual" is a term made by a group of people who follow the Minecraft Youtuber Dream, almost to the point of worshipping him, called Dream Stans. They are basically saying that they are attracted to Dream. This is not a sexuality and they have done this just for attention. NOT VALID!
P.S. another group of stans who follow JellyBean have come up with "Jellysexual" basically meaning the same thing as Dreamsexual, but for JellyBean. This is even worse than the previous one though because JellyBean is A MINOR! They are basically saying they are attracted to a minor! This behavior is dangerous now that it is spreading to more people like the stans. Neither of these are valid! Please spread the word!!!
TL;DR: Dreamsexual is NOT valid and needs to be stopped