Credit: Christopher Polk/Getty Images Photo: Nathan Fillion and Kate Luyben at the 2010 VGAs

When our favorite (read: hottest) TV stars fall in love, we feel one of two things: a) excitement for their happiness or b) excitement for their happiness, mixed with a good ol’ heap of jealousy.

The latter is how we feel whenever we read about our resident sleuthing stud Nathan Fillion and his latest main squeeze, Kate Luyben. If you’re thinking, “Um, who is that?” — don’t worry, we did, too. Kate is actually an actress — a C-list one, perhaps, but an actress nonetheless — who has appeared on True Blood and The 40-Year-Old-Virgin (as, um, “Girl With Videotapes”).

Kate has also had brief stints in Two and a Half Men, Arrested Development, Criminal Minds and Intolerable Cruelty. And...she’s played a prostitute in about a third of the movies and shows she’s been in. Interesting...

It looks like things are pretty serious between the two actors. Kate’s been spotted on Nathan’s arm at many an event over the past year, including the American Music Awards, the 2010 Emmy’s, and um, a trip to Bora Bora.

And, in an interview with New York magazine late last year, Nathan gushed about Kate, calling her “lovely,” “wonderful,” and a host of other adjectives with positive meanings.

So, what’s her secret? How did Kate win Nathan’s heart? An interview in Star mag in December quoted an insider who said she gives him ample space for his fave pastimes, like playing video games and hanging out in his “man cave” (yes, that’s what he calls it). “He’s cute and charming, but very boyish,” says the insider. “Kate lets Nathan be himself.”

Sounds like a pretty healthy relationship to us. But hey Nathan, if you ever get bored, we’ll let you play our Wii anytime.

Source: NY Mag, Celebitchy