Aventurine never gets attached to someone. Probably because of his past. He's afraid of loosing once again someone he cares about. But he couldn't help but fall for you. You were treating him with kindness, not caring that he's a gambler.
Aventurine always felt a weird wramth in his chest when he's around you. His heart is beating faster and he seems to not be able to be the cooky self he usually is when he's around you. He knew he had fallen for you, but was scared to tell you. What if if you don't love him back? What if your friendship/partnership was ruined the? He couldn't risk loosing you.
What he didn't know was, that you liked him back. You gathered all your strength up and asked him on a Date. He was surprised, but didn't said no. The date was great and you became a couple. He was still scared of loosing you, but he still wanted to be with you.
A few months has passed and Aventurine was clinching onto you like a puppy. He had dreamed of you, dying in his arms and now, he wouldn't let you go, no matter where ever you go.