Yes. You can. I know it is some kind of application that lets you track your husband. But the trick is that it won't actually track him, it will track the phone. My dad has an Android and he was able to track my brother and I's phones. Now, it might not be accurate. Sometimes it shows that the phone may be in the next building. One thing you have to do is check out how it will work. Always read the reviews first. It might or might not work if your husband's phone has a contract with another company.Good luck!
It is unethical. If you have any problem with your husband seek legal advice but do not blame iPhone. Or better you may also go get unwind somewhere else.