Someone who is so perfect but you can't tell them for some reason
"That girl is painfully perfect!"
"What does that mean!?"
"It means I think perfect but it's painful that I can't tell her I think it"
When someone is so perfect its painful.
Such as the way they look at you, the way the smile, the way they talk, their voice, and just them in general makes you happy and gives you butterflies. They're so perfect they can change the atmosphere with just a smile.
Person 1: They're just...
Person 2:...painfully perfect?
Person 1: exactly!