"When a woman buys a drink, she's either trying to seduce you or break up with you."
Oh, sure, that isn't invariably the case, but it does hold true a hefty percentage of the time. Yes, I speak from bitter experience. My ex of exes, "The Evil One", tried to break up with me* at least once a week throughout the four or five months we were together; I always knew it was coming because these were the only occasions when she ever tried to buy me - or herself, or anyone - a drink. (For an ardent feminist, she was surprisingly comfortable with patriarchal customs that require a man to pay for everything!)
* It was, in fact, probably rather more than once a week, but not all of them were completely in earnest: perhaps the majority might be better characterised as teasing threats, or ominous discussions about the possibility of ending it. Even full-on dumpings were, it transpired, not necessarily in earnest. The first she repented of after 12 days, the second in a matter of minutes (she claimed she'd only done it "test" my reaction). 'Volatile' hardly seems an adequate word for that relationship; but the good times were very good.
I would also like to point out that these frequent ruptures were rarely if ever precipitated by any 'offence' on my part. The dear girl just wasn't comfortable with committed relationships.