well i have MANY friends that are Scorpio ..and I've dated two Scorpio men too..im a Capricorn btw.. yeah to know if hes in love, his eyes would be fixed on you no matter where you are or no matter what situation you are in. Even if you look back his way he would not glance away as he is full of confidence. Sometimes, they'd pester you and insult you very honestly even if you did nothing wrong to them that's one sign he might be interested. Next, he would tell you his secrets..that, is quite an obvious sign hes in love because he finds it extremely hard to trust ANYONE. The biggest hint could be when he is extremely sensitive and caring when you tell him your problems and listens to all the things that make you sad and unhappy. He will look deep into your eyes and that's when you know his feelings are real and also especially when you ignore him or get angry with him, he never EVER gives up on asking for your forgiveness or pleading for you to talk to him again.