Darn, it was just on but I wasn't paying attention... I'm sorry! But I think so-called 'kinky sex' is what she was referring to. I have a problem with this.
For starters, she has never personally analyzed Travis, so I think such a statement is really irresponsible on her part (and I do agree with her sometimes). Second, as a behavior analyst, lawyer and her doctorate in criminal justice, she seems an odd person to reflect on human sexuality and what does/doesn't qualify as "dark".
I'm a total layperson despite growing up around and raised by mental health professionals/educators (talk about the cray cray!

) and took several courses in child development/psychology, so I basically know squat.
I DO know that sexually/mentally healthy adults have an enormous range of fantasies and turn ons.
I've not read but have heard about the 50 Shades series... I know people do all sorts of role-play, dress-up, like handcuffs, restraints, being tied to trees, (Dr. Jordan familiar with Chaucer's Canterbury Tales?) some people like being degraded verbally and otherwise... and some people don't like any of this.
Between consenting adults, none of these things signifies anything 'dark' or bad about their characters when part of a healthy sex life. Nor does disliking wilder stuff signify something wrong, either.
imv, Travis enjoyed raunchy/baudy conversation. He also liked to sing (badly) which I found sadly poignant and endearing.
He also seemed (in that short snippet in time) to be apologetically critical of other people that (to me) spoke more of frat-boyish immaturity and ignorance than some sort of drastic foreboding of darkness in his soul
Its really sad that MSM gets all googly-eyed about sexual lives that were never meant to be headline news and recklessly analyzed/picked apart by experts who should know better.
Oh I tried to find the Dr.D episode online for you, no luck.