Some might argue he taught his daughter a lesson in personal integrity and living up to your word.
Of course, but the real world involves contracts & contractual language. A temporary tattoo was probably within the contractual terms, arguably ambiguous, but still living up to one’s word & personal integrity. If not, then maybe there was no meeting of the minds &, therefore, no contract.
Nevertheless, if both thought that the clear intention was for a permanent tattoo, then there was a meeting of the minds even though not clearly or overtly expressed.
Although imagine the family dynamics if such a lesson results in lawyer-like arguments about any promise or implied promise made by one family member to another in the future.
Exploitation of loopholes that one party was not aware of at the time the agreement was made may be within fulfilling the agreement, but tends to reduce trust between the parties.
Perhaps it’s a cultural thing, but for me if my daughter were to ask, “Dad, can I get a tatoo?” we’d both know she’s talking about a permanent tatoo. I’m very curious to hear from other posters if they naturally assume “tatoo” defaults to temporary rather than permanent.
Where did “default” enter into this discussion ?
“Exploitation of loopholes” ??? Try “implied” versus “expressed”. Perfectly reasonable for both to have considered the option of a non-permanent tattoo.
And, of course, law, lawyers & contractual terms have no place in our society.
I love loopholes!! 
It is not perfectly reasonable because the difference between permanent and temporary tattoos is far greater than the range of options for the daughter to fulfill her end of the bargain. If I make a deal in which I would have to give someone “a thousand bucks” then my attempt to fulfill the debt with Monopoly money, although perhaps technically correct, would not be reasonable, and would be seen by a court as bargaining in bad faith if the other party was offering something of actual value.
I’m society? Sure. In family? Not in mine.
In some families, lawyers and attempts to exploit loopholes become expected. Examples would be nasty divorces and fights over estates and inheritances (where it is no longer possible to ask the giver what s/he really meant).
But most people would not want their families to go through these types of events.
I say way to go to the dad!! If he promised that then he knew what he might be getting himself into. 
I got a tiny bit teary at the end :(( What the hell is wrong with me?! It’s going to be a long 4 years for me.
@Marian, I had a similar experience with a “punishment” I used on my son when he was in early elementary. He had a friend over and they were using bathroom language at the table. I told them their words were appropriate only for the bathroom and that they’d have to take their lunch in there to eat it if they didn’t stop. Well, you can guess what happened.
@Publisher, contracts are certainly part of the real world, but so are covenants and “spirit of the law” vs legalism, especially among friends and family. Not everything is reducible to transactions, thank God.
@Massmomm : I just snorted my coffee out my nose at #31. Thank you very much.