What do I do about him?

My boyfriend is my best friends brother, we have been dating for a couple days now, and my best friend has been ignoring me, she says that she feels like a third wheel around us, I don't disagree with her, her brother is too into me! he doesn't let go of my hand, hes always hugging me and kissing me, and he never gives me any privacy! I broke my old boyfriends heart when I dumped him last month, he just got over me with a new girl, and I kinda miss my old boyfriend now, I shouldn't have dumped him, I still have feelings for him. But my new guy, Quinn is so nice to me! He treats me like i am a precious jewel to him! And when he hugs me, I feel safe ,but I guess I am jealous of my old boyfriend. Whenever people were around Joe (my old boyfriend), he would always show me off, but when we were alone, I was kinda like his buddy to watch a game with. And Quinn makes me feel like I belong with him, and we have been sorta friends for 3 years now, but his sister and I have been friends for since second grade!!! What do I do about this?