The person can change their gender if they want to, but they're born with one, which is compatible with their sex.

XY.

Have you tested them?

???

Like did you get a test to see your chromosomes or are you assuming?

When you're born, you're given your amount and kind of chromosomes.

I'm pretty sure I'm an XY, which can also be assumed by one, once they see my abnormally large penis.

Do proceed.

Pretty sure isn't definite

It is.

I either have a penis or I don't.

I'm either XY or XX.

Im pretty sure this water wont kill me

Is not the same as

I can't and won't change my chromosomes.

This water wont kill me

Are you for real?

I'm a male, my chromosomes are XY.

When you're born, you're given your amount and kind of chromosomes.

And hence, your sex.

Your example was irrelevant.

You were tested at birth?

When you're born, you're given your amount and kind of chromosomes.

Can I get a source I vaugely remember that they don't test it

My cock is your source.

Literally.

Im pretty sure you can have a cock and have other chromosomes

Rare

But I think possible

I'm not XYY nor XYY.

If I were, I would know.

Have you tested?

When you're born, you're given your amount and kind of chromosomes.

Or are you assuming

When you're born, you're given your amount and kind of chromosomes.

When you're born, you're given your amount and kind of chromosomes.

Are you identifying

When you're born, you're given your amount and kind of chromosomes.

When you're born, you're given your amount and kind of chromosomes.

Source please

I may be wrong