No; there are lots of men whom you may think are gay, but are not. There have been a couple in my circle - and even the gays’ own ‘gaydar’ had it wrong.
(I’m not concerned with ‘repression’ or whatever else may be going on in an individual’s inner psychology. I just care how they conduct themselves in society.)
I’m not saying they are gay. Their homosexuality is suppressed, but it reveals itself in female mannerisms.