How these two meet
You went deep on the first evening and neither of you found that strange, which is its own piece of information about how the rest of your lives have gone.
Depth is not the problem in this house. Depth is the only thing either of you trusts.
What neither of you has, and each of you assumes the other one does, is a floor. Scorpio goes down expecting to hit something. Pisces goes down and does not, because Pisces has never had edges in that direction and never claimed to.
So Scorpio keeps testing for where Pisces stops, reads the absence of a wall as an invitation, and goes further. Pisces keeps not stopping, because stopping would need a boundary they have never located, and reads the going further as being finally, properly met.
Both of these signs were handed a second ruler long after the system was finished. Neptune was found in 1846 and Pluto in 1930, and neither has ever been visible to the naked eye.
The pair the geometry was actually drawn on is Mars and Jupiter, and those two sit at the far ends of one measure: Jupiter turns back once every 1.09 years and Mars only once every 2.13. One of you revises constantly. The other holds for two years and then turns without warning.
For Scorpio, the work is stopping before the wall, once, on your own, without being asked to.
For Pisces, the work is naming one limit out loud even though you are not certain it is real. Say it anyway and find out afterwards.
The question
How far down did the two of you go before either of you spoke?
One conscious action
one floor, out loud
Each of you name one thing that would be too far. Not a rule for the other person: a description of where you personally stop.
Neither of you may test it this month. Say it, write it down, and leave it standing there.
The bodies people name when they describe the two of you were invisible to everybody who built the system you are standing in. The pair underneath is one that revises constantly and one that does not move for two years.
Which of those have you each been assuming the other one was?