We are genetic males.

Correct!
Given that I can't find a policy on BreastNexuS that forbids the use to genetic males, BreastNexuM is specifically for genetic males.

I am not talking about one's perceived gender or genitals (TG/TS, in case) but about one's genetic markup.

Then, why do you use these sites? If you are after info about how to grow boobs, knowing that genetically male bodies behave differently from genetically female bodies, you should have little or no interest in reading the other forum. If, instead, you just want to perv on picture of boobs, well...

Some of us, including some admins like Lotus, use both forums to help people regarding the biochemistry of some substances. Most of us, though, including transgender and transsexual people would have no reason to read both.

Again: it's not men/woman. It's XX and XY. If you are intersexed then it makes sense to have an account on both.

There is more than one gender or two or three but they should be equal.

There is more than one gender or two or three but they should be equal.

True, but NBE (or BE in general), doesn't care about what your gender is or what you want to dress like. It's a matter of chromosomes and there's little you can do to argue with those.
I always found it correct and clever that the definition for BreastNexuM is "Breast Growth for GENETIC Males".

I am more than my chromosomes XX XY.

Thanks for your responses. But there is no disputing our websites are binary.

Thanks for your responses. But there is no disputing our websites are binary.

Nothing stopping you from creating your own website.

The split was with the intention of making BreastNexus a women-only organisation.  But we live in a society where single-sex organisations are subject to significant disapproval and therefore often impractical.   Perhaps this is liberation for some, and a curtailment of freedom for others.  What I totally agree with is it is better to admit or welcome people on the basis of how they behave than on the basis of what's written on their drivers license.

I thought it was because all the perverts?

What if my stated sex on my driver's liscense is Non Gender Conforming?

What if my stated sex on my driver's liscense is Non Gender Conforming?

It means your state Department of Motor Vehicles (or whatever they call it in your state) has an option for "Non Gender Conforming" on their driver's license and that you chose it.   That's it.  Nothing more.