Ignore them and enjoy your lasagna
Some guys really do have a tendency to say the wrong things at the wrong time. For instance, the OP shared a story of a jerk restaurant guest who was being super-rude to his date. Out of nowhere, the guy loudly calls for one of the waiting staff to come to their table. He then asks the waiter whether his girlfriend looks fat or not loudly enough for everyone to hear.
Out of sheer embarrassment, the woman started crying her eyes out. Who would do that to their girlfriend in public? If she asks you if you think she looks fat, the right answer is always “no.” But the dinner wasn’t all bad. The OP enjoyed a nice lasagna.