Are they dating in real life? Don't you think it's just for REEL rather than REAL?

They have never confirmed nor denied a relationship offcam but have been vocal about the fact they are mutually exclusive to one another - they aren't seeing other people. As for the real/reel question, I believe Kim and Xian do a good job at keeping their fans entertained on screen and do their best at keeping what they personally have off screen a private matter. Of course as fans, every one wants their OTP (one true pair) to be official, and every tabloid or host wants to find out 'the truth' from big names in the industry because that's just what the biz is. Personally, I have been a fan since 2011 and it's easy to see they're very comfortable with one another. I've watched it grow from awkward hugs to the two being inseperable. They clearly have a great bond off camera as their chemistry and comfortability just exudes and translates on camera. Their families are also heavily involved in their 'mutual understanding' and both Kim and Xian will post and talk about what they do as a pair off screen but with a limit. Read between the lines and I promise you, the answer is right in front of your eyes. Though they won't vocally say it, it's perfectly clear what they are...

*GIF credits to fuckyeahkimmychiu, a Tumblr worth checking out! Just click the GIF above.