The feeling is uneven. It lasts if you keep adjusting, not if you wait to match.
The two of you
Scorpio. You feel real when it is honest, even if it is heavy. People see the intensity. They trust you with the thing they will not say elsewhere.
Gemini. You feel real when the conversation is alive. People see the quick mind, and someone who can talk to anyone.
What wears it out
Small talk that asks you to be fine drains you. So does a secret kept from you.
Being told to pick one thing and stay there drains you. Silence that means you should stop asking does too.
Scorpio feels it first and explains later and does not like to be moved once settled. Gemini needs to talk before it feels real and adapts quickly, and may not finish.
Nothing in the two signs locks on its own. Some days you understand each other. Some days you are solving different problems in the same room. Together, it shows up as sex and what they cannot take lightly. The other way around, it shows up as the work of an ordinary day.
This is the answer people want before anyone knows a birth time. Two real people have more than a sun sign. If it matters, cast both charts.