I dont know if other people are supposed to reply here, but I dont agree with this responce. Sex isnt everything, and there could be a handful of things he is insecure about, and he will open up in time. Like for instance maybe he is religious, or is a virgin, or is afraid cause your are older, there are tons of reasons. It is actually a good thing that you have discovered that you have trouble communicating before having sex. Just let him know that you know he must have a good reason and you are there to talk when he is ready. Sex is great, but it complicates things, especially when someone isnt ready. If he loves you, be greatful you dont have a douchebag who only wants sex. Just be patient 🙂