It isn't something they thought too hard about. After everything that's happened, perhaps they think it's better not to consider things too long. They're trapped on a ship with little to do but wait—and wait for what? Even that is unsure.
It isn't something they thought too hard about, but it wasn't all that spontaneous, either. There were times when shoulders brushed as they stood too closely on the deck, times when fingers touched and paused in passing, and when dark brown eyes lingered just a little too long on lighter ones. Intensity passed between them like electricity.
So it didn't come as a surprise when they pushed into their cramped, dirty quarters with their mouths melded together and body flush against body. There were clothes tossed to the floor and gasps and soft moans and long fingers tangled in sandy brown hair and a sweet kiss before oblivion.
But then three years have passed and those dark eyes—so much colder than they had been way back then—were looking down a well to meet those lighter ones. There were questions and hurt and "I think I deserve to know why you're going to shoot me in cold blood, brotha." And then there were memories flashing by, of touches and electricity and lingering glances and sweet kisses. Don't you remember?
Realization dawns slowly and the cold thaws slower—just enough to allow blurry sight through the haze. Yes, I remember.
There was another kiss. It isn't something they thought too hard about, but it's more bitter than any that had come before. Three years is a long time and they've both aged so much and it comes as no surprise.
It's not really true that time heals all wounds—some will linger forever.