If a guy maintains eye contact with you while talking, it shows that he is interested and has eyes only for you.
If he can’t stop smiling and laughing around you, you are putting him in a good mood. He enjoys being around you. He is also trying to build a positive rapport with you.
If he remembers tiny details about you, it shows that he is interested in you. Remembering things that you wouldn’t expect him to remember is a great sign that he is thinking about you and he wants to stay connected.
Jealousy is a strong feeling that’s hard to control. If a guy gets jealous when he sees you talking to another guy, it shows that he likes you and wants all your attention.
Introducing you to his friends and family means he likes you. If he is impressed by you, he wants to show you off. He is proud of the fact he knows you.
He may ask about your life, your hobbies, your friends, etc. If a guy does that it means he wants to get to know you. Questions show that he is interested and curious. He wants to learn about you and what makes you tick.