There is a strong correlation between romantic involvement and shared stressful experiences. Its a movie trope but there have also been studies done. The last one I read about was in Scientific American in the late 90's/early 2000's. You can check 'romantic relationships and stress' on scholar.google.com and find lots of hits.

There is also a correlation between having an excuse to be close together and opportunity. This apparently got pretty bad for Microsoft employees on the road such that the company issued guidelines. But I don't know if corporate was any more or less affected.