He and they are probably happier when his party is not in power but twice previously an election result has made his party's support necessary to provide the country with a government. Both times he has given its support to the party with the most votes as did Peter Dunne each time his party was in a similar position.
Peters has given no indication that he will do so this time. Indeed, he says he does not agree with National's contention that having won the election it has a "moral right" to continue governing. But Peters knows that every government needs to be accepted by voters who did not vote for it. They might not like what it does but they need to be able to accept that it is the rightful government. That has to be uppermost in all parties' considerations this week.
If Peters installs a Labour-NZ First-Green government it will be the first time under MMP than New Zealand will be governed by parties that came second, third and fourth past the post. This was liable to happen sooner or later with proportional representation and constitutionally it is perfectly legitimate but more than a million people who voted National in the final count might have to be persuaded the outcome is fair and just.
Nobody knows whether they will be persuaded until MMP is put to this test.
Being part of a new government might have more appeal to Peters and his party than joining one that is nine years old. However, National's vote in the final count is 44.4 percent, which is only fractionally below the 44.9 percent it had nine years ago. No government has sustained levels like this since the 1960s, none has won a fourth election since 1969. To deny it a fourth term could be a hard call.