It's probably a defective camera. Send it to me and I will make sure it is disposed of properly. :mrgreen:
On a more serious note, taking photographs with mixed exposure levels is a classic problem. You would have the same situation if the couple were under the shade of a tree but with a non-shaded background beyond the tree. You also see this happen indoors when there is a window to the outdoors in the background.
The image essentially wants two different exposures... one for the subject, and another for the background. You can't have both in the same exposure (unless you shoot an HDR series and merge them.) BUT... it's an easy problem to solve when you think about it.
You can't do anything about the light in the background unless you plan to wait for it to get dark outside. But you can EASILY do something about the lighting on your subjects. You need to bring up the lighting on your subject to be a bit closer to the lighting of the background. You don't necessarily want them to be lit exactly the same because you'd lose the contrast... you just need to reduce the number of stops of difference between the background and subject.
If you meter the background and meter the subject, you may see a couple of stops of difference in exposure values. If you can get the subject to within about 1/2 of a stop, they'll look darker, but not "obviously" darker. This is easy to do with either (a) a large reflector (easy to use on a bright day and the reflector provides very soft light... a collapsible reflector isn't very expensive.) or (b) you can use flash for fill lighting. When I use flash, I tend to set the "flash exposure compensation" (not exposure compensation for the image itself... just the FLASH exposure compensation) to "-1" as a good starting point. That means however much light the flash needs to provide to fully illuminate the subject, the flash will fire at 1 stop less (50% of the light). This provides fill light to decrease the intensity of shadows so it still looks somewhat naturally... just not so extreme.
You could meter for the subject and allow the background to be over-exposed, but you don't want it to be blown out (don't want the whites clipping). You can also meter the background, then meter the subject, then set an exposure which is half-way in between (assuming they are not too far apart) and adjust in post processing because as long as nothing is clipping you have a lot of room to correct it later. Although I find it's a bit easier to just use a reflector.