Just open & close them. Try to mimic the way he is doing it. It can be for a couple seconds or a couple minutes, even. Sometimes it can be slow, soft, & sensual. And sometimes it's fast and hard. However he is making out with you ; is usually how he wants to be made out with, too. If he's going to fast {[which, personally I DON'T LIKE]}, and it feels like he's trying to swallow you. Stop! And, don't be mean, but be like, this is how I want you to kiss me. Place your hand on his face {[preferably right]}, and have your thumb in front of his ear -not ON it- & your other four fingers in the back of his ear -not ON it-. You can have your other hand running through his hair or even do what I do, tickle his neck. {[AKA: Gently caress it with your fingertips.]} Usually, [most] guys like when you rub their neck softly, or run your fingers through there hair. {[It usually surprises them. ;] If you catch my drift.]} Guys have tons of nerve endings in there head & it will undoubtedly cause a reaction. {[A good one.]} -But, in simpler terms: Go with the flow. Don't try too hard, and take your time. Why rush? :]
