oscillate between (two people or things)
To waver or go back and forth between two different, often contrary people or things that once is trying to choose. I keep oscillating between the job in New York and the one in Los Angeles. You've oscillated between Steve and Tommy long enough—they deserve an answer one way or another.
oscillate between (someone or something and someone or something else)
to swing between (choosing) someone and someone else; to swing between (choosing) something and something else. Fred oscillated between going to college and getting a job. The boss oscillated between John and Roger.