An observation on transient military metaphors

As noted in a previous post, I have been involved in a 40th reunion with fellow (and I hasten to add, former) professional killers (Australian and New Zealand entrants - class of '67 - to the then Royal Military College Duntroon). A rollicking good time was had by all, and in the course of the various events, I was reminded of vernacular expressions which we commonly used then, but rarely use now. In due course, I will be pleased to resurrect some which have a particular pithiness and which evoke appropriate imagery. But there is one I will not be tempted to use again as it is (and was) puzzling. The expression in question was used to disparage someone who was seen to be currying favour with a superior. The supplicant in question was said to be "pissing in (the superior's) pocket". A moment's reflection on this expression reveals its singular inappropriateness as a metaphor for currying favour. If someone was seeking a favour from me, the last thing I would recommend is that he or she should "piss in my pocket". Of course, such an expression could never emerge today as it is clearly sexist, whatever it's other possible merits. Think about it.