A cute mf (a cute mother f*cker), is not an insult like calling someone a mf, it's a compliment. It is calling someone so cute/perfect that you can't describe it. It can also be used to show that your love for someone is ♾️.
That girl is one cute mf.
You are a cute mf.
You are one cute mf.
A term a person would say when they are making fun of a situation or they are sarcastically naming something cute when they didn't really think it was.
"Aww they are drooling their saliva all over each other in public, cute up"