What are some ways to keep the conversation interesting between the guy...

[sweetpea143]

...I'm interested in? Theres this guy that i really like alot, he's my ex, and it feels like he just wants to keep things on a cool level of "just friends"..we've had alot of issues yet i feel like he's not getting over them all the way and holds back with me sometimes because of it. He's a dude that jokes around alot and can be very funny. From what I see compared to other people, he treats me differently. Like with his friends, he's mr. popular, but with me its almost like o..well shes here or like whateva. There alot of people pursuing me but I choose to stick with him, but its difficult because our conversations are borderline bordem where I have to come up with different things to talk about, yet with his friends (male and female) it seems he starts the conversations, is happy, and sometimes can joke sexually with them, and has been to the females rooms multiple times. He still hangs out with me, but I feel hes doing it just to be nice..idont know what to do and I need advice..i feel like the answer is obvious but i dont want to give up on him.