He hasn't proven otherwise.
Fact: Trump had three (relatively) long-term relationships with women.
Even he has admitted this.
It is only when that fact is taken in context with another fact that the questions inevitably arise:
Fact: Trump has never proven he is not a woman himself.
He has never done the one thing necessary to put the rumors to rest, and something tells me he will never be able to:
Fact: He has never produced the long form.
I've been told very recently that it's missing.
As one leading Democratic media whore put it,
"I assume that Trump is not a lesbian. I assume he is probably a man. But I have to get rid of the word 'assume.' I don’t want there to be a question. I think it would be wonderful news for everybody, including me, if the [male genitalia] is found. But at this moment there is no [male genitalia]. Some people say it exists, and if it exists, even worse, why isn’t he showing it? So I would like to see a [male genitalia], and when Melania and everybody else say they think it exists, why don’t they produce it?"
Another drug-addled member of the Professional Left chimed in,
"Occams hatchet is performing a valuable service here. He is attempting to help Trump out of a jam. You can't say occams is a kook left-wing junker. OH realized the problem that Trump faces here with credibility. He's giving him a chance here to establish some credibility by producing the [male genitalia].”
(Note: "Junker" refers to those who maintain that until he shows his junk, doubt remains as to which team Trump plays for.)
Not that there's anything wrong with that . . .