A lot of the paparazzi think that celebrity relationships are a joke mainly because of the number of couples that they have caught cheating. There are some couples who are only faking it for different reasons. Some are obviously pissed at each other and there are others that are obviously not going to last. The paparazzi have already seen a lot of celebrities and they are able to tell if a relationship is meant to last or not.
There are some paparazzi that have hounded the celebrities too much that they have gotten hurt in the process. Some have been punched while others would need to be brought to the hospital because of angry celebrities.
The reason that paparazzi seems to treat celebrity relationships as a joke is actually for a very simple and logical reason. Paparazzi photographers make their income by selling their photos and stories to different magazines from People to the awful and poor quality magazines you often see while standing in the line at the grocery store.
Any kind of pictures that seem scandalous, even if they are not, the paparazzi can twist into a meaningful story which grabs your attention. The easiest way to do this is by manipulating the photos of stars in relationships, particularly new relationships.