LOL @Ren. Yes, I should have consulted here....bad, coldi! XD
The champions armor isn't the only armor that obscure like that, so I often have my PC's talk to Fen in very light armor, the "finery", or small clothes if I'm feeling silly.

. So I am guessing you were playing one of your m!Hawkes in a Rivalmancy, eh?
If you do tag along with Tallis after the cave, and flirt more at the end of the DLC, you do get a fun little response from Fenris. I only do it if it fits the particular Hawke I am playing. For example, there was no way Castor was going to help Tallis, and he wouldn't have even considered flirting with her (ok, I did do it once at the very beginning just to see that fun little reaction from Fenris, "What did YOU have in mind..!?"
But I reloaded, and went flirt free through the DLC. Tallis would not have garnered that kind of reaction from him. I have only played two Hawkes that fully flirted with Tallis, since they did enjoy trolling their lovely broody elf. HA!
Zev on the other hand, I almost always flirt with except for any import that had Zev as the Wardens "one and only". Since those bug out (grrrr), I just don't flirt, and I never bring Issy on those runs either. Castor and Falon were the only two who didn't flirt with Zev that didn't have a romanced Zev import....it didn't make sense for their characters.