Male Gemini and Female Scorpio are the worst match in the zodiac.

These exact polar opposites are commonly a fatal attraction ending in irreparable differences.

Scorpio females attract the Gemini male with their quick witted banter, their pure physicality, a hint of menace and their wild unrelenting passion for verbal engagement.
This is mistaken by the Gemini male as intellectual engagement on all levels, and thus subject to certain restraints of objectivity.
The Scorpio is blissfully free of such concerns and this creates an uneven playing field.

The arguments that provided the initial rush in the relationship soon dissolve into pure verbal jousting on a mundane level and  the bubble bursts degenerating into name calling as each attempts to assert their individual realities. These relationships ultimately become acrimonious and rarely last long.

In nature, when a scorpion is cornered it will sting itself to death rather than be killed and this is mirrored in scorpio behaviour. This self-destructive tendency can prove too much to handle for the clear cut reasoning of the gemini mind.

Don't get me wrong, the fault lies in the match-up not the individuals, who for most part are often unaware of the reasons that things fell apart.

or at least.......... that's what mine was like... and I know of at least six other similar stories.

i am married to a sagittarious, we are constantly
fighting and butting heads, tempers collide, love/hate thing, but gotta be together, he is not loyal, understanding, he just dont get it, he thinks im bipolar as with most gems, but again cant live with him cant live without him, i also dated a leo that was similar to my sag. and dated an aquarius that seemed to be 'the one' we never fought and always had a blast but i couldnt commit? so im confused! who is the right one!

Sagittarious is the sign that contains the most beautiful people in the zodiac. They look great, are very accommodating, are exhilarating to be with and can leave a Gemini breathless. They are loyal to their desires but not to others. They will most likely explain that at the outset of a relationship but not in the way a Gemini can immediately understand. Their disclosure of their real nature is generally seen as relating to purely physical issues. They are highly sensual and can cloud the Gemini mind with many delights. I believe they love deeply but are always prepared for instant gratification with others. They are drawn by Gemini depth of thought and often feel that their Gemini partner provides a steadying influence on their lives. I don't  believe they view relationships as necessarily exclusive, moreover they consider their physical morality has no bearing on their partnership's integrity at all.  
A good test is to place a bag of lollies in front of a Sagittarian and watch how many they eat. Sometimes they will offer them round quickly returning the bag to its original position and then eat the rest but most times they will eat them all without noticing. often when there are a small number left they will laughingly notice and draw everyones' attention by jokingly stating that "you've gotta be on the ball if you wanna eat".  
I don't think they ever intend to eat "everything offered" but, as they see themselves as a totally free spirit in the cosmos, they can't resist the temptation to indulge in the moment.
Sagittarius in many ways is the eternal teenager.

Leos on the other hand will always share food around often going hungry themselves. Their need is regally subjugated to provide for their immediate subjects. The trouble is they expect the same level of consideration from those around them and may become critical in their efforts to enforce their standards on others. They are totally loyal and expect the same in return.
They are born rulers and as such can be difficult to satisfy. When satisfied however they are benevolent, generous and love with their entire being.

My longest and most satisfying, while most demanding relationship has been with my darling Leo wife (for the last 20years).  It has been a great learning curve for me.
To truly understand relationships Sunsigns are not enough. You need to consider each persons ascendant sign for further insight.
Even greater depths can be investigated by a complete Astrological birth chart.

From my experience, a Numerology (Birth and Name) chart provides the greatest insight into personalities and their behavior. Study your own first and then your partners and you will immediately see the correspondences and the differences.
With this Knowledge you can plan how to overcome any issues that do arise from a balanced perspective. (This stuff works!)   Full understanding can be achieved by using Astrology and Numerology together. This also helps you consider the health aspects of your lives together.

I have been with my Scorpio wife since 1976. We still hold hands, go out on dates, etc. Of course she never forgets anything, even if I do. She is on the cusp, libra/scorpio.

I am gemini sun sign and husband is taurus..till now we are doing awesome..I guess it is not necessarily limited.