Saisons means "seasons". While it might seem like a common word, its use in this song is particularly poignant and adds a layer of depth to the lyrics.
Vitaa sings, "Combien des saisons nous séparent" (How many seasons separate us). This line beautifully conveys the passage of time and the enduring distance between two people, making it more evocative than just saying "how much time".
"Je te tiens" is a duet between Vitaa and Slimane about two people caught in the same ache of distance and doubt. Each verse mirrors the other almost word for word, one voice singing "je me sens seul" and the other "je me sens seule," as if they're living the same loneliness from opposite sides of it.
The chorus turns that mirroring into a plea: neither of them understood the rules of this relationship, but they're asking the other to come back anyway and hold on. It's less about blame and more about two people who miss each other more than they can explain, still reaching for a hand to hold through the confusion.