Help I have some questions !?!?!?!?

Well I was making out with my bf and he always has me sit like I am straddling him well that brings up two questions I am taller than him when he does this so I have to move alot when we kiss to where it's like I am dry humping him is that why he likes that and other than the having to dry hump y do guys like that and how can I do it better and I am not complaining I love doing this I just need help