Nathan Fillion stopped by Conan on Sept. 25 to dish all about the love of his life. "So pretty!" he squealed. But things haven't always been so easy. "It started eating me alive," the Castle star admitted.
You may be surprised to find out who Nathan is talking about!
![](http://pinterest.com/pin/create/button/?url=http://www.wetpaint.com/castle/video/castle-star-nathan-fillion-opens-up-about-his-tumultuous-relationship-weve-had-counseling-video%3Futm_source%3Dpinterest.com%26utm_medium%3Dshare%26utm_campaign%3Dvrl&media=http://static.wetpaint.me/castle/ROOT/photos/9272012-113627-AM-3697291661611239531.jpg&description=Castle Star Nathan Fillion Opens Up About His Tumultuous Relationship: "We've Had Counseling" (VIDEO))
