London, Aug 31 : Sandra Bullock and Ryan Reynolds, who were pictured spending quality time together, are still insisting that they are "just friends".

The 34-year-old actor was seen leaving the actress' residence in Hollywood Hills, following a three-hour visit, and zooming away on his customised Ducati after reversing it out of Bullock's garage, the Daily Mail reported.

`The Proposal' co-stars have been friends for over a decade and have been spending an increasing amount of time together since helping each other through their break-ups last year.

Bullock, 47, also made a surprise appearance at the premiere of `The change-Up' to support her friend, and the duo were also spotted enjoying a hike near the `28 Days' star's father's home in Wyoming with Reynolds playing father figure to Bullock's son Louis.

The pair are also rumoured to be joining forces to produce a new animated television show, `And Then There Was Gordon', and they are in talks to voice the lead characters in the show about an average boy surrounded by "prodigy siblings". (ANI)