What to do with my tongue when kissing him?

This is a really stupid question (I know), but me and this guy began making out at his for a movies the other week and he started using his tongue, and admittedly I'm not super experienced with my tongue! I had no idea what to do, and for those who say it comes natural, well it didn't. I'm just curious as to what the best thing to do with your tongue is when kissing a guy? I don't want to shove it down his throat but I don't just wanna let him do all the tongue work, any tips???