Based on the Stefan/Bonnie scene from the most recent episode.
What's the last thing you can remember?" Stefan asks softly
"I guess I remember being in that cave and Jeremy was trying to pry the cure out of Silas' hands." Bonnie looks up at Stefan in slight confusion, "Please tell me he got it."
Stefan looks down sorrowfully and Bonnie knows something is up "We didn't get it, did we?"
"Bonnie, there's something you need to know about Jeremy." Stefan begins sadly.
X
When Stefan realizes that Bonnie doesn't remember Jeremy's death his heart drops. He hates that she will have to relive the devastation again, but knows he has to tell her. So he does and he feels an ache when she collapses into sobs.
Stefan can't help but think that this is his fault. Bonnie had been obviously been spiraling downward for a while now and no one really noticed. When she had been so upset earlier in year, he had planned on being there for her, but it never ended up happening. He had been so focused on Elena and later on his own problems that he had forgotten about Bonnie.
He watches Bonnie for a few more plan-filled moments before sliding closer to her on the bed. He climbs into the bed, shifting Bonnie so he can sit behind her, pulling her against his body. He slips an arm around her waist, using the other arm to shift her so her head rests on his chest. His hand also slowly moves up and down her back in what he hopes is a soothing manner.
As Bonnie cries into his chest, her tears dampening his shirt he makes a vow. He decides that from now on he's making Bonnie a priority. She needs to know that someone is looking out for her. Not because she lends magical help, but because she's important to him.
They had had a pretty good friendship at one point. At least until she stopped trusting him and he's only now realizing just how much he wants that friendship back. So he lies on the bed with her hoping that being here with her will be a start.