MandMaud
So I'm not the only one linking lily with breasts!
Well, shape-wise, if you take your glasses off, it makes sense. In fact I was taken aback when I found that it's supposed to refer to male genitalia, not female. Though that area can be seen too... But instinctively lily seems more female - at least to modern Western eyes. We are used to thinking of flowers as a girly thing, after all, which they aren't in all cultures, but in mine (boring white western northern hemisphere ) almost no one associates any flower with men.
Except, maybe, the red hot poker, Kniphofia uvaria. https://jariya078.files.wordpress.com/2014/02/dsc02679.jpg.
Seriously though, I do get pretty confused by the way people (people with more experience, that is) insist sometimes on sticking to one set of meanings, at at other times are happy to decide meanings intuitively.