Pellaeon had promised himself he wouldn't do this. It was embarrassing, unbecoming of someone his age, and he would never live it down if Thrawn ever found out.
But it has been an hour since he had retired to bed, and he needs to sleep. One way, or another.
So he swallows his pride and assures himself that Thrawn's trip off the Chimaera means he won't be caught (although his absence is what put Pellaeon into this position in the first place), and leaves the bed to walk to Thrawn's closet.
There is a shirt he knows is in there from earlier today, having been put back after Thrawn only wore it an hour before having to take it off to change. It would be unnecessary to waste cleaning supplies on it, he had decided, and though Pellaeon had rolled his eyes at the time it would serve a purpose now.
After flipping through a few hanging uniforms, he finds it. Generic Imperial gray, short sleeved, and only slightly rumpled. He pulls the shirt from the hanger and holds it up for a moment before pressing its collar against his nose and inhaling.
He can still smell Thrawn on it, and he smiles despite himself.
He tries not to think about what he's doing as he brings the shirt back to bed with him and snatches up the pillow that's on Thrawn's side of the bed. With deft hands he slips the shirt over the pillow like it's a case and lies down on the bed with it.
Still trying to ignore how pitiful he must seem (honestly though, Thrawn was only going to be gone one night, could he really not make it that long), Pellaeon curls up on his side and wraps an arm around the pillow. He presses his face near the shirt's collar – around where Thrawn's shoulder should have been if he wasn't gone – and tries to relax as he breathes in the familiar scent.
It's not the same, but it must be close enough because he falls asleep within minutes.
The sight is so endearing that when Thrawn comes back early to find Pellaeon still wrapped around a pillow with his shirt on it he simply leaves the room, deciding that he can let the man save a little face in regard to this.