Oh. Snap. Canada's most-popular frequent flyer (sorry — "travel loyalty") program just announced that it will be partnering with one of its ex-partner's rivals — just one day after turning down said ex-partner's offer to work things out.

Aeroplan is moving from Air Canada to Porter Airlines, bringing with it some five million active members, not all of whom are thrilled by the news.

Release from #aeroplan parent company says #Porter Airlines will provide up to 60% of its seats for Aeroplan miles redemption. That’s a lot. And it should help Porter’s bottom line, too. Crazy few days in the #travel and #Airlines biz. Back to square one for #AirCanada?

— Jim Byers (@JimByersTravel) August 3, 2018

Aimia Inc., the Montreal-based company that manages Aeroplan, announced in a press release on Friday that it would be designating Porter as the "preferred Canadian airline to issue Aeroplan Miles," as soon as its contract with Air Canada ends in July of 2020.

"The arrangement includes an extensive cooperative marketing program targeting existing Aeroplan members, with an emphasis on members who travel on Porter routes," the release reads.

"Porter passengers will then be able to earn and redeem Aeroplan Miles on all Porter flights, plus across the growing Aeroplan collection of more than 75 travel and retail partners," it continues. "This includes international airlines covering much of the globe."

I knew there was a reason why i was hanging on to all those @Aeroplan points. Can't wait to use them on @porterairlines

— Jordan Thoms (@Lummix66) August 3, 2018

Aeroplan members will be able to pay for Porter flights with their miles, once the agreement comes into effect, and points from the Toronto-based airport's existing VIPorter loyalty program will automatically be converted into Aeroplan miles.

The move should come as welcome among people who frequently travel to cities served by Porter, but those who are keen on collecting long-haul miles are less than thrilled.

Ditto for Canada's west coast.

And all the @aeroplan members in Western Canada are asking "Who the hell are @porterairlines" and can I get to YYJ from YVR on them? pic.twitter.com/dFFk0lmswH

— Ian Williams (@Scscottish) August 3, 2018

Had this happened a few months earlier, Air Canada would have seemed to come out of the relationship ahead.

The massive international airline (Canada's largest) famously dumped Aeroplan last year to start its own in-house loyalty rewards program (though customers will still be able earn and redeem Aeroplan Miles from Air Canada until 2020.)

Then, just last week, Air Canada announced that it wanted to buy Aeroplan back in a deal worth approximately $2.25 billion.

So @AirCanada sold off @Aeroplan 15-ish years ago for about $1.5 billion and now they are buying it back after saying they would drop Aeroplan a year ago.

The Air Canada and Aeroplan relationship status: Complicated.

— Robert Snell (@robertsnell) July 25, 2018

Aimia wanted more money than Air Canada and its financial partners, TD, CIBC and Visa, were willing to offer, according to the Canadian Press.

Negotiations broke down before the takeover deadline at midnight on Thursday and, one day later, Aeroplan announced that it was moving to Porter — a much smaller, but far better-rated airline.

"Today's announcement with Porter is consistent with our strategy to further differentiate and strengthen our air offering come July 2020," said Aimia CEO Jeremy Rabe in today's release.

"By adding Porter, Canada's top-rated airline, as a preferred airline partner as of July 2020, we will deliver our members industry-leading value on many popular routes."