Argthtjtr

And if it can also be used by women, I still feel vulgar using it.

Using the phrase is unladylike.

Semantically, it means the same thing (regardless of gender); but historically is only used by males due to its vulgar undertones.

Therefore, excluding the affiliated taboo, there's nothing wrong with a woman using the phrase.

Are women allowed to "take a leak" ?

take a leak tv: to urinate. (Crude. Often objectionable. Usually in reference to a male. Leak is the mildest and piss is the strongest.) "I gotta go take a leak. Back in a minute."; "We stopped at a rest area so old Harry could take a piss." See, the Free Dictionary, Idioms and Phrases “take a leak” definition from, McGraw-Hill's Dictionary of American Slang and Colloquial Expressions.

In comment I noted, with amusement: We "leak", too. But we only use the expression among those who won't be judgmental. But, after returning to the page and noting the ‘state of play,’ I’ve decided to respond in answer-form.

The idiom may be considered “vulgar”, but I believe that can only be in a linguistic sense, as in definition 2, below. While the definition of the idiom in discussion, noted above, marks the expression as, “crude”, consider the alternatives, for either gender.

Men routinely employ this expression without self-consciousness or peer censure. Beyond, “Fellas, I got to go to the men’s room”, in my experience “take a leak” [manly and earthy] is more popular than, “excuse me for a moment, gentlemen, but I must urinate” [formal but effete] or “Dudes, I’ll be right back. I gotta take a piss”, [generally crude]; while, “Hey fellas, I gotta powder my nose”, is just completely off the table! [pejoratively effeminate].

For women, aka, the “fairer sex”, who are socialized to be linguistically (if not morally) prudish and self-censorious, the options are more tenuous. Beyond, “Excuse me, but I need to visit the ladies room” [formal] or “Be right back girls, I need to go to the bathroom” [minimally formal], we are left with, "Excuse me, but I must powder my nose” [if we happen to be socialites or Hollywood starlets].

I believe that the American culture (I cannot speak to other cultures), in general, has been pervaded by a native puritanical sensibility, wherein references to bodily functions are never socially acceptable and must be negotiated with euphemistic terminology, the more abstract, the less vulgar and acceptable.

Personally, among my family & friends (i.e., the people I love & who love me) such an expression is acceptable and not considered crude or vulgar. Among others, I tend to be more circumspect (i.e., I "tinkle.")

Vulgar adjective

1. marked by lack of taste, culture, delicacy, manners, etc: vulgar behaviour; vulgar language.

2. (Linguistics) (often capital; usually prenominal) denoting a form of a language, esp of Latin, current among common people, esp. at a period when the formal language is archaic and not in general spoken. see, Collins English Dictionary "vulgar"

My personal opinion is it's high time we stopped differentiating between male and female behaviour, and most certainly should drop the term 'ladylike'. Men are men and women are women, and I feel 100% free, as a woman, to use any expression I care to when needing to empty my bladder - the only constraint is whether I'm likely to offend the people around me by using some of the coarser expressions, and there are many that I have used whenever I felt like it (within the aforementioned constraint), including the usually-considered-masculine 'slash'. And I'd add I definitely sweat...

If you don't feel comfortable using such an expression, then refrain - it's all down to what you as a person (rather than female) feel comfortable with. If it helps, I give you full permission to say it!

I know a woman that routinely says “gotta take a piss” or gotta take a leak. It’s unladylike but it seems kinda funny for a woman to say. Maybe she dares to be different and expresses herself a little different.