There are many reasons why this could have happened; such as first time jitters can make for an awkward time. As with most everything communication is key. If you're able to be intimate with someone, you should be able to discuss sex with them also. Perhaps if you showed him what and how your likes, your desires, perhaps that could help too. However, as much as sex is a part of a couples life there are more things than sex that can make or break a relationship. Without knowing exactly why you were disappointed this is my suggestion. Expand your knowledge while expanding his. As you have said you want to be with him, so think long and hard about it all. Good luck to you.