when in men's clothes?

Same here. Maybe It's because you're cross dressing?

It's probably because people perceive you as a female and yet you are wearing mens clothes - it's a manifestation of "male fail" and it's usually a pretty good indicator that it's time to take the next steps in your transition. You are creating a conflict in people's minds and they stare at you until they work out the conflict.

Eva Marie is right. It often happens because they are confused about what they see in front of them. It's probably a good sign that the hormones and how you act, look and carry yourself are starting to make them question what they see. Hugs
Mariah

I have good posture even tho I'm 6ft 2inches.got so bad one day I walked past a couple at a car boot said is that a boy or a girl I kept on walking