I've never personally been stood up at a restaurant (knock on wood), so I can really only imagine how embarrassing it would be the find yourself on the sad end of an empty table.
And it just goes without saying that that feeling would definitely be amplified if happened on one of the biggest, most arbitrary yet somehow still socially relevant days of love of the year: Valentine's Day.
If I was in a restaurant and saw someone had been tragically stood up by their not-so-special Valentine, it would definitely pull on my heart strings.