Biting and Licking Guys' Ears?

i was with my guy earlier and we were messing around. I wasn't gonna have sex with him and was already clear on that. anyway, I started biting and licking his ear. I automatically noticed he got really turned on right away. and he started touching me even more passionately and he smiled and said I shouldn't do that because its dangerous.

i always hear and read that doing that to a guy is a big turn on. (which is why I did it). I'm just wondering how much exactly? like why is it? what does it feel like for the guy/what goes through his mind...or body ;)