What do a blunt truth-teller and a person who feels everything have to say to each other? Quite a lot, and much of it lands sideways. Sagittarius and Pisces form a square - ninety degrees of built-in friction, the aspect where attraction and irritation arrive in the same package. There's real magnetism here, because each has something the other lacks, but the pull comes stitched to a recurring collision that doesn't resolve so much as get renegotiated.
How Sagittarius and Pisces collide
The elements explain the heat. Fire wants to state the thing plainly and move on; Water absorbs the thing and carries it for days. A Sagittarian honesty that feels bracing and clean to the archer can hit a Pisces like a slap, and the Piscean tendency to feel around a subject rather than name it can strike Sagittarius as evasive or moody. Neither is wrong - they're running different emotional operating logics, and the square makes sure they keep bumping into the gap until they learn to translate. When they do, Fire gives Water courage and direction; Water gives Fire depth and a reason to slow down.
Two shape-shifters, no anchor
Curiously, they share a mode. Both Mutable, both adaptable, both restless in their own register - which cuts two ways. It means neither insists on being right the way a Fixed sign would, so fights bend rather than lock. It also means neither is the anchor, so the relationship can wander, dissolve its own plans, and lose the thread of what it was building. Two shape-shifters need to consciously appoint some structure, because left alone they'll each keep changing shape to accommodate the other until nobody knows what they actually agreed to.
Beyond the sun signs
As friends they can be oddly devoted, each fascinated by a way of being so unlike their own. As lovers it's the classic grow-or-grate square: stay, and it sands down your worst edges; leave, and you'll swear you were never compatible. Don't let the sun signs settle the question either way - the Sun is one instrument, and it's the Moons, Venus, and Mars that decide whether the whole thing plays as a chord or a clash.