Written communications are full of clues if you're trying to figure out if a Gemini is really into you.
Words are serious business to the Twins, so take note of the sign-off on emails or texts. That "Love" or "TTFN" was chosen deliberately!
Verbal interaction is just as important. A once-chatty and convivial Gemini who is now not so much could mean the bloom is off the rose. If times are troubled, he or she may suddenly be "too busy" to spend time with you.
Chalk it up to a fascinating experience and move on if a Gemini lets go - when they're done, that's that.