"I'll stay with you," he told her, looking utterly defeated. It was at this - his willingness to sit out with her at the expense of not fighting alongside his friends, a prospect so out of character for him - that she understood how genuinely desperate he was to protect her.

The Marauders & Lily have a hypothetical conversation about life after Hogwarts.

"Harry's eye's darted nervously between Sirius and Remus, and in them, Sirius saw the same bright green staring lovingly at James as he talked about something he was passionate about..." Canon-compliant Reverse POV from OOTP, wherein Sirius is reminded of memories he'd long forgotten.

"She smiled at the faint snoring now coming from Sirius, fast asleep on one of the rooms squashy armchairs. It was his idea, to spend Christmas at Hogwarts - what with it being their last year and all. She hadn't pegged him the nostalgic type, but as she'd learnt, they'd surprise you, these boys."

If butterflies fluttered through Lily, they absolutely erupted through James. The feel of her lips against at his wrist pushed him to a level of intoxication far beyond what the contents of the flask already had.