Optimus had found you when you were trying to defend yourself from a vehicon, and barely made it out without harm, and being human made you even more vulnerable in his optics, and spike a feeling possessiveness he had never felt before. And he always felt like having you near when you were at base.

Odd. He had never been like this before.

He started having the need to hold you close to himself... constantly, occasionally give you the affectionate kiss on the head, and when you were on the platform with Jack, Miko, and Raf, on the couch, he would just pluck you up from the couch, not before giving the other 3 a nasty glare and walking off with you.

It was another day at base, and you were on Ratchet's shoulderplate, having a decent conversation with him, before Optimus came back from recon, and spotted you on Ratchet's shoulder, and that's when he snapped. He immediately snatched you off the medic's shoulder and stormed off with you in his servos, and had you trapped in them.

He had made it to his habisute and put you in a rose display glass (with breathing holes, of course) and made sure it was shut tightly before setting it down on his desk (gently) and sat down in his chair, and put his finger on the glass, almost lovingly, as he propped his elbow on the desk, cheekplate resting on his palm

"You're so, sweet, and mine."