Is it OK for me to try to re-initiate things with my previous a week after breaking up with my ex?

So I dated these two individuals I'm going to just identify as X and Y. So X came before Y. I just broke up with Y and I'm thinking of flirting with X to try and resuscitate our long lost relationship.
Is it OK for me to try to re-initiate things with my previous a week after breaking up with my ex?
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