In February, Frontier Airlines announced its plan to purchase fellow budget airliner, Spirit. But JetBlue’s surprise competing bid for Spirit sent the three airlines into a messy, public love triangle. WSJ’s Alison Sider reports on how the possible mergers will shake up flying in the U.S. Further Reading: - JetBlue Boosts Breakup Fee, Pledges Dividend in Bid to Woo Spirit Holders   - Spirit Airlines Delays Shareholder Vote as It Considers Frontier, JetBlue Offers  Further Listening: - Frontier, Spirit and the Future of Low-Cost Airlines  Learn more about your ad choices. Visit megaphone.fm/adchoices