Some people just click with you instantly. Others are very clearly your nemeses from the get-go. Then there are those who fall somewhere in between, who you think you can tolerate, but only for a little while. And once that thin shell of tolerance cracks, frustration starts to seep out.
According to the Astrotwins' comprehensive compatibility tome Compatibility Secrets: How to Get Along with Anyone (Yes, Even THAT Person), those who fit this description may belong to the sign that squares your own (aka, is separated by three signs on the Wheel of the Zodiac). Based on their compatibility theories, this is the sign that you really struggle to mesh with. There might be an air of friendly competition between you, or you might not agree with their deepest principles. They aren't completely terrible (let's be real, no sign is), but they aren't BFF material either.
As sound as this theory is, it doesn't mean it's impossible for a Gemini to find common ground with (or even befriend) a Virgo, but some of their personality traits and values will be at odds. In some cases, a little tension can produce serious chemistry — you might kind of, sort of, hate each other but still recognise where you really connect. In others, that same tension can build up into real conflict — sometimes, annoying little differences are too great to overcome. This is the way of frenemies.