Sexual addiction or not

My husband an I have been together for 10years this past April. We have been married for 2 year. we have 3 kids I am 28 and he is 33uears old. My husband an I have had two threesome in our relationship. We are trying to conceive and he wants us to have another and even a possibility of swinging. Am I the crazy wife for thinking he has an addiction or something. I can't see myself having sex with another man while my husband's in the room with another girl and I'm married I'm not the type to do things like that. We've had 3 somes why does he want more. Please tell me I'm not the crazy one . Maybe this is normal I just need answers.