JustinH: Let's examine the actual thought process that got you into trouble. (For now we'll overlook the part about you going to dinner in your oil changing outfit.)
1) You laughed and boasted to a blonde friend of your girlfriend about your capabilities: you were trying to score points (with both girls) and inflate your ego.
2) You caved and permitted the girl to violate your exact instructions about bringing cash, not supplies.
3) You didn't confirm with an online reference that the new filter part number was correct and didn't compare the new filter against the old filter until after it was too late.
Under the circumstances, you are quite lucky. Next time, let your big head do the thinking.
1) You laughed and boasted to a blonde friend of your girlfriend about your capabilities: you were trying to score points (with both girls) and inflate your ego.
2) You caved and permitted the girl to violate your exact instructions about bringing cash, not supplies.
3) You didn't confirm with an online reference that the new filter part number was correct and didn't compare the new filter against the old filter until after it was too late.
Under the circumstances, you are quite lucky. Next time, let your big head do the thinking.