If Scorpios feel that they have some rival or someone who is above, they will never be 100% happy. He seems like a very, very sure person about everything, but deep down, he's not so sure; deep down, he's a more insecure person than he seems, and in love, or you give him 1000 or better, don't give him anything.
Scorpio also goes step by step. He wants someone in his life with whom he can open up completely without fear of what he might think. Inside the head of Scorpio, there is a Universe that not everyone is able to understand, so when Scorpio feels that he/she can be himself/herself all the time is when it takes a great weight off of him.