Key and the President strolled together on the South Lawn, chatting about Michelle's garden and the putting green President Dwight Eisenhower put in during the 1950s.
(It was removed in the 1970s and another was put in by President Bill Clinton in 1995.)
Obama bumped Key up the White House visiting schedule, which may not have been too difficult.
Key revealed it was Obama who forced the US Navy to allow a New Zealand warship, HMNZS Canterbury, to dock at Pearl Harbour for the first time in 30 years.
What's the point in being commander-in-chief if you can't give orders?
The fact that US Pacific Command relegated New Zealand to a civilian dock away from Pearl Harbour in the Rimpac exercise two years ago shows how symbolically important it was to the US Navy to keep New Zealand at a distance.
The biggest notch in Key's belt was Obama's recommitting to the Trans Pacific Partnership as a comprehensive deal — the elimination of all tariffs — and putting a November deadline on it.
That is a signal to foot-dragging Japan to step up to the table seriously or step out of the deal.
New Zealand and the US both ultimately want a high-quality TPP — the kudos for Key was that Obama used his visit to put the blowtorch on Japan over TPP.
So what concessions did New Zealand make for the stroll on the South Lawn?
The US persuaded New Zealand to be linked to a heavily worded statement issued by the White House about China's territorial disputes in the South China Sea, in language New Zealand would never use.
"In discussing the need for [diplomacy] and dialogue to resolve disputes, the two leaders rejected the use of intimidation, coercion, and aggression to advance any maritime claims."
Key chose two subjects to mention inside the Oval Office to the press: TPP and China. All that will be noted in Beijing.
The statement was put out as a White House "fact sheet" rather than a joint statement, which could give New Zealand diplomatic distance.
There is nothing unfair in using those terms to describe China's actions, and plenty of others have.
But New Zealand hasn't.
It has simply said that "anything that lifts the level of tensions is unhelpful".
The White House's fact sheet may suggest either that New Zealand has toughened its stance or that the White House wants it to.
Friends come with benefits, but they can also be demanding.