Worth the risk
Opposites on the wheel, and in your case that reads as recognition rather than war. Gemini collects the details, Sagittarius chases the wider picture, and each of you quietly wants what the other does without trying. Both mutable means plans change constantly and neither of you minds — the flat tyre becomes the story you tell for years. What a 70 is pointing at is depth: two restless signs can spend a year having a wonderful time and never once have the difficult conversation. Book the trip, absolutely, but answer the question when one of you finally asks it.
Fire and air — you feed each other. Plans get bigger in the telling, and somehow still happen. What carries the two of you: you are heading the same way, so the five-year conversation will be short. And you talk the same way — the long message and the two-word reply both land.
Try this first: Ask where they see themselves living in five years. Compare notes.
That is the Sun only. Your Moon and your Rising move these numbers more than the Sun does, and almost nobody knows theirs — the app reads all three. 18+
Gemini and Sagittarius, asked properly.
Are Gemini and Sagittarius opposites in a good way?
Mostly, yes. Opposite signs share an axis, so you are chasing the same thing from different ends — Gemini through detail and conversation, Sagittarius through distance and experience. That makes for a friendship with excellent stories. The gap shows up in depth, not in liking: both of you start better than you stay.
Do Gemini and Sagittarius get bored of each other?
Not of the adventure, sometimes of the intimacy. Two mutable signs can keep a calendar full for years and never have the conversation about what this actually is. Boredom here usually means the relationship stopped moving, so the honest question is whether you want it to go deeper or just go somewhere.
What trips up Gemini and Sagittarius most often?
Bluntness meeting quickness. Sagittarius says it raw; Gemini fires back something sharper and funnier, and suddenly it is a scoring contest. Neither of you meant harm, but both of you are fast enough to do real damage. Slow down when it stops being a joke, and apologise specifically.