In order to do that you would have to break the symmetry somehow. One or both of you would need to change frames either by proper acceleration or by moving near a large mass.

In the case that only one person spends time in two reference frames, the latter will have had less time pass by their clock than the stationary person.

If you accelerate in a symmetric fashion — you both turn around at the same time and in the same way and head back together), you will find that you both actually agree on how much time has passed.

More fundamentally, there is no absolute speed whatsoever. Both of you are equally justified in saying you are stationary and the other one is moving at 0.995c and the universe will agree with both of you.