Ohh I get it. Your 'male' friend is a transman? So now, male and female mean nothing aswell as man and woman? So confusing.
I do get where you are coming from, but deliberately blurring sex/gender is not helpful in any discussion

Also your friend sounds to be transsexual, not transgender. There is a huge difference.
Edit. Sorry if this post comes across as harsh, just read back and the tone is not how I intended at all but I am arguing with a friend who is trying to tell me that transgender people are actually born as the sex that they wish they were, science is wrong, males and females are no different in any way and that the dick can indeed be a female organ and we should accept that whilst declaring that lesbians should not reject a partner based on their biological sex but gay men can and should?! Bizarre argument thats riling me somewhat.