Most of his fail points are not his fault really:
Fail:
Not being dressed appropriately for a fancy restaurant or date.
Defense:
He didn't knew he was going to go to a fancy restaurant, or on a date.
Counter:
It is Christmas eve, the thing screamed date...
Fail:
Not preparing enough money to afford the fancy restaurant's prices.
Defense:
He didn't knew he was going to a fancy restaurant!
Counter:
Nothing really, he should have avoided it and suggested a different cafe, but since he didn't knew this was going to turn into a date, he didn't knew any alternatives.
Fail:
Lying about sweets.
Defense:
Coffee is the cheapest option, and even that was expensive, he had to save face somehow.
Counter:
Nothing really, at best he could text his sister and ask her to drop him some cash, but that would probably explode on his face.
Fail:
Calling her mom cute.
Defense:
Only a fail because he has never called her cute.
Counter Defense:
Yeah... that one was awkward, but it could have been worse.
Fail:
Weird fashion theory.
Defense:
Not really a fail, it allowed them to bond over something, plus it had him calling her cool and fashionable in a sneaky way.
I think that given the circumstances he is managing quite well for someone that found himself suddenly thrown on a date on Christmas eve while looking like a stalker with no money, and dealing with insecurity.
Actually he is doing great!