I want him badly but I'm in a relationship
Why do you want him if you are currently in a relationship?
He is handsome, witty and caring.
If you are in a relationship, then you should remain committed to that person. If you find others attractive and want to be with them then you should break up your current relationship.
I think I can have both.
No, you can't. The second your other half find out about this, your relationship with them is done. You need to make a choice and not be greedy about "having it all".