Antonyms for the phrase "bought a one way ticket" could include "booked a round-trip ticket," "planned to stay indefinitely," or "reserved a ticket with an open return date." These antonyms suggest a different approach to travel, one that involves planning and commitment to a specific return date or a more extended stay in a particular location. Choosing a round-trip ticket, for example, indicates a readiness to return home or to another destination after a certain period of time, while keeping a ticket with an open return date suggests flexibility and a desire to explore multiple destinations.