finding other people sexually attractive

✨sav ✨
I'm having a bit of a debate with someone over his topic,
I think that the majority of men and woman have sexual thoughts or find others attractive that are not their partner/husband/wife. I don't think there's anything wrong with it as long as your not cheating. So I think having fantasies and gettin yourself off isint a big deal. 
Someone else thinks your a pig, trash and no better than an animal if you have sexual thoughts about anyone other than your spouse or if you masterbate with these thoughts of others. 
What are your thoughts?? Do you think it's wrong to think of anyone else but your spouse in a sexual manner??