You dont lie like this to a person you actually care for.
I don't think this is completely true.
My wBF lies constantly, and it actually ended our relationship. So I completely and definitely understand how damaging lying is.
But, I also have been in IC for my own lies. My lies stem from my co-dependency issues. I lie because I don't want to hurt people. And those people are people that I care about. I tend to lie more around people that I care about more. I know it doesn't make much logical sense, but it's my issue that I'm dealing with.