In the BDSM community, many people have fixed ideas about how a dominant or submissive should behave and attempt to inflict their opinions on others. They disparage others by saying "if you were a true dom you'd do x". The others in turn disparage them by calling them "twue" (a supposedly effeminate version of "true"). Also spelt "twoo" and "tw00".
"Joe told me I wasn't a proper sub because I wouldn't do what he wanted - even though it was revcolting"
"Don't worry about Joe. He's a twue dom and a twue asshole".