"Cis" also means you agree that you were born to be naturally submissive, dainty, and to like ribbons and sparkles.

Gender is the set of social roles, rules and expectations assigned to a sex. "Gender identity" is the idea that a persons 'gender' is an innate trait, something you are born with. Transgender (to a transperson) means they were born with the opposite sexes roles 'innate' to them. Cis means you were born with the 'correct' set of innate gender roles.

If you agree that you are 'cis' then you're saying that you and all women are naturally inclined to wear make up, be sexually attractive to men, be a mother, cook, clean, wear dresses and heels, like the colour pink, be bad at math and spatial reasoning, hate sports and getting dirty, etc. etc. All the things that transpeople say are reasons they "knew" they were a woman.

My personal rules on pronouns and names have become very simple - I won't tell someone elses lies for them. If he wants to say his name is Sheila, and the he's a 'she', that's fine. Free speech. But I won't tell his lies for him. I call it like i see it. "She" is a small lie, but it's still one, and it's one that will be utilized later against other women ("everyone ELSE calls me 'she' you bigot!") and when trying to access our spaces. I don't see a reason to help him with that.

Additionally, I really believe that a lot of these transpeople are mentally ill. They're operating in a delusional state, some as a result of trauma. They really do believe they ARE female, and the doctors and everyone around them confirm that belief. If your friend came up to you and said that he IS King George of England, he fully believes that, and his pronouns are now 'your majesty', would you go along with it 'out of politeness'? Or would that be enabling a harmful delusion? Would you instead, as kindly as possible, say "It might upset you to hear this, but you're not a king, you're not from England and I won't call you 'your majesty' because doing that would harm you."? That's a delusion which really won't do him any physical harm. Enabling a persons delusion of being the opposite sex can REALLY cause them physical harm as they go down the path of 'physical' transition. Your being "polite" could give them lifelong medical problems, or even kill them in the long run.

So ask yourself, are you really 'being polite' or are you just avoiding confrontation?