Pluto wants to go to the bottom of things and stay there, uncovering what love looks like once every mask is gone. Jupiter wants to keep moving, chasing the next horizon before the last one has even settled. Put them in a relationship and you get one partner asking "but what does this actually mean for us" while the other is already texting about a weekend trip to somewhere neither of them has been. Scorpio pushes for depth. Sagittarius pushes for breadth. Neither is wrong, they are just answering different questions about what love should be doing at any given moment.
There is real magic here when it works. Scorpio's intensity gives Sagittarius a reason to slow down and actually feel something instead of just narrating it cheerfully from a distance. Sagittarius gives Scorpio air and light, proof that not every silence has to be interrogated, that some things can just be fun. Mars adds heat to Scorpio's want, and that meets Sagittarius's fire in bed without much trouble at all.
The fixed and mutable clash shows up in small domestic moments. Scorpio wants to finish the argument tonight, get to the truth of it, no loose ends. Sagittarius wants to sleep on it, or better yet, go for a drive and talk about something else entirely. That drives Scorpio up the wall, and Scorpio's refusal to let anything go unexamined can feel like an interrogation to a sign that just wants to breathe.
Honesty is the bridge. Sagittarius says what it means, Scorpio eventually trusts that this bluntness is not betrayal, just a different dialect of loyalty.