I don't keep the entire consular storyline on my hard drive, but it's a pretty common complaint on the internet about her. Once she professes her feelings for you, you can only delay the inevitable.
It's a common complaint because many male Consular players are idiots - although the usual crummy BioWare paraphrasing doesn't help.
There comes a point in the Nadia conversation chain with male Consulars when she says something very close to "You're more than just my Master...you know that, don't you?" IIRC, there are three choices: one that affirms it, one that shuts her down gently ("this isn't appropriate", which ends up being the line "You're very kind, Nadia, but we can't do this - I'm sorry."), and one that kind of steers a wishy-washy path that keeps the romance open.
Picking the affirmation or the wishy-washy dialogue choice will keep you in the romance and lead you to that infamous three-flirt convo. Shutting her down will end it, and keep you on a friend path.
Believe it or not, there are a lot of male Consulars who haven't romanced Nadia.
Now, a very similar thing happens with Corso; his romance starts with dialogue that doesn't appear to be romantic, and isn't marked with a [Flirt]. It's the scene where he offers to get wasted with the Captain. Saying yes locks a female Smuggler into a romance, saying no stays out of it. But this isn't a forced romance, it's a ninjamance.
Interestingly enough I can never bring myself to kill Master Timms on Belsavis.
He's too rare. A Smart Jedi!
He's virtually unique in the Sith Warrior storyline. Chapter 1 especially was just a cavalcade of moron Jedi.