A look at http://www.dictionary.com/ revealed the following:

Definition of a 'gentleman':

1. A man of gentle or noble birth or superior social position: "He's too much a gentleman to be a scholar" (Aphra Behn).

2. A well-mannered and considerate man with high standards of proper behavior. See Usage Note at lady.

3. A man of independent means who does not need to have a wage-paying job.

4. A man: Do you know this gentleman?

5. gentlemen (-mən) Used as a form of address for a group of men.

6. A manservant; a valet.

And I'm particularly interested in the 2nd definition, the reason I'll explain later but first, let's look at the definition of a 'lady':

1. A woman who is refined, polite, and well-spoken: She may be poor and have little education, but she's a real lady.

2. A woman of high social position or economic class: She was born a lady and found it hard to adjust to her reduced circumstances.

3. Any woman; female (sometimes used in combination): the lady who answered the phone; a saleslady.

4. (Used in direct address: often offensive in the singular): Ladies and gentlemen, welcome. Lady, out of my way, please.

5. Wife: The ambassador and his lady arrived late.

6. Slang. a female lover or steady companion.

7. (Initial capital letter) (in Great Britain) the proper title of any woman whose husband is higher in rank than baronet or knight, or who is the daughter of a nobleman not lower than an earl (although the title is given by courtesy also to the wives of baronets and knights).

8. A woman who has proprietary rights or authority, as over a manor; female feudal superior. Compare lord (def. 4).

9. (Initial capital letter) the Virgin Mary.

10. Awoman who is the object of chivalrous devotion.

11. (Usually initial capital letter)
a. An attribute or abstraction personified as a woman; a designation of an allegorical figure as feminine: Lady Fortune; Lady Virtue.
b. A title prefixed to the name of a goddess: Lady Venus. –adjective

12. Sometimes Offensive. being a lady; female: a lady reporter.

13. Of a lady; ladylike; feminine.

Combining definition 2 of a gentleman and definition 2 and 3 of a lady, it will be safe to assume that a gentleman is a well-mannered and considerate man with high standards of proper behavior towards a lady who in this case is a woman who is refined, polite, and well-spoken and/ or woman of high social position or economic class.

Therefore, I think it is perfectly justifiable to reserve gentlemanly behaviours to the female species that exhibit the qualities worthy of being called a lady and I mean socially, not biologically.

The reason for this? I have had enuf of ill bred female species demanding or expecting to be treated like a lady simply because they are born female.
I'm sure there are guys out there who let a lady (from here onwards refering to the female human species unless otherwise stated) move up the escalator during peak rush hours, or hold that door open while they enter or exit a lift or building, or offer their seats to someone pregnant, but let me ask a question, how many times do you get a 'thank you', or even a smile for your trouble?

Most of the time, my simple token of social graciousness goes ignored, my existence completely un-noticed. It's as if it is expected of us, the males, to offer seats and hold doors. WTF?

Of cuz you may say a true gentleman does not expect gratitude and should treat all ladies like a lady (here I mean females who are refined and well spoken), well let me ask you this, do you ladies (I mean female species) treat all males as a gentleman (I mean a man of gentle and noble birth)?

I'm sure your answer will be 'If he behaves like one', or 'Unless he's cute', or 'Unless I want to make him mine', or 'Unless he treats me like a lady'

So you have it. DO NOT expect or demand to be treated like a refined, well spoken lady unless you behave like one. We guys most certainly do not owe it to you to treat you nicely, unless you happen to be one of the following:

1. Our girlfriends

2. Our mothers or relatives

3. The girl whom we are hoping to impress with the aim of turning you into our girlfriends

4. Our female friends whom we think deserve a gentlemanly behaviour

To those who fall outside these 4 categories, you can open/ hold your own doors, fight for your own seats and take your own time and squeeze your own way up/down that City Hall or Raffles Place MRT escalator