Sources add that Kristen insecurities were building up when Robert was away with Resse Witherspoon in Los Angeles for Water for Elephants. A source close to her commented “Kristen would get worried if Robert did not answer her calls and felt that Robert was with Resse".
On the other side, Robert would get upset on hearing that Kristen was having a wonderful time on the sets with her On the Road co-star Tom Sturridge. Robert and Kristen seem to be extremely passionate about each other. Though both of them had decided to get hitched, they postponed their plans as Robert felt that they were too young to get married.
With the constant media attention it seems difficult for them to be with each other and both of them tries hard not to divulge any details about their affair. Insecurities often crumble a relationship so we suggest that they should both try to spend time in each others' company.