I'm going to preface that I'm from Germany where going dutch is absolutely the norm and not really a red flag, except for maybe during the first date (and even then ...). Still, I was an absolute clown for letting this happen to me.

When I would go for dinner, drinks, lunch, whatever with a guy, I wouldn't really want to hassle the waiter by having them write two seperate checks, so while we were waiting for the waiter to bring us the check/tell us the total, I would initiate pooling money on the table so we could pay quickly and easily.

Usually I would already know the exact amount I owed, meaning what I put on the table was my share of the bill plus a generous tip, usually around 20 percent. Totally normal so far, right? But then, and this has happened with TWO SEPERATE GUYS on MULTIPLE OCCASIONS (basically 100% of guys I seriously dated lol), the guy would add his half, but either leave no tip (why would they think I would pay for the entire tip??? also their meal was always more expensive than mine because I'm a vegetarian) or leave less than they owe so that the total would still work out because I "overpaid" by leaving a tip.

Here's an example: If my drink is 8 euros, I'll add a 2 euro tip so that it totals 10 euros. The guy would order an 11 euro drink and pay 10 ... The waitress would then get a whole euro as a tip on a 19 euro order, while I would have subsidized his drink. The amount is negligible in this example, but this would also happen at rather nice restaurants.

When I would confront them, they would laugh, not apologize and obviously not correct their behaviour. The audacity is mindboggling to me, though perhaps the fact that I went out with them more than once and would cry over them not wanting me is likely even worse ...