What you do need to do is understand why he cheated on you, how he feels about it, and if there was anything about your relationship that needs solving that might have made him more likely to have sex outside the marriage. If he wants to be in the marriage, you need to find a way where you can accept his apology and create a new family where you can learn to trust again. You should know that most men who have been unfaithful have only been unfaithful once or twice, and so this behavior is unlikely to happen again. Whatever you need to make you believe that he's truly sorry, whether it is staying home with your more, talking more, discussing what happened more, whatever you need to hear. But you have to believe that something can happen and not happen again.
People make mistakes and people have appetites that sometimes work against their own best interests.
If you truly want this marriage to have a chance, you have to fight against bitterness and fear or embarrassment. No one else is in this marriage but you. Forget about what it looks like to anyone else and work together to salvage the good things you have together. There's often so much pressure in the middle of lovemaking that it's awkward to start giving directions, particularly if you've never done anything like that before. A sexy and sound way to get what you want is to have a romantic dinner and start talking about what you would like to try or what are the favorite things you do together, what you find thrilling, and what's okay but not your favorite.