(Cover) - EN Showbiz - Robert Pattinson and Kristen Stewart are planning to seal their romance with commitment rings.

The Twilight co-stars have been dating for around two years and appear to be inseparable, often going no longer than a few hours without speaking.

A friend revealed earlier this year that they constantly call and text each when working on different projects.

And now it has been reported the pair wish to show their dedication by taking part in a special ritual despite the fact that marriage is not an option yet.

Theyve vowed never to spend more than ten days apart and theyre going to fly away to a ceremony where they will present each other with commitment rings, the source told More magazine.

They worry about losing each other. They feel too young to marry, but want to celebrate that theyre in love more than ever.

In the past Robert and Kristen have made every effort to keep their romance low-profile. However, in recent months the couple have been seen in public more regularly. (C) Cover Media