Eliot had a bit of an idea. "Sorta. You two used ta be together then bad shit happened. 'm guessin' Angelus was involved." When you had a vampire with a soul who had a beast inside of him like Angelus... it wasn't exactly a wild guess to think it may have caused problems.
Eliot looked at Buffy, reading her body language as best he could, and the feelings he was getting off of her.
He softened his voice a hint, lips twitching into that little "hey there, it's okay, I promise." grin as he reached out, brushing a bit of hair from her face. "I've got a feelin' it messed ya up pretty badly..."
His gaze dropped to her inattention (or overattention) to her food. "Not hungry? Or not what you wanted? I could make you somethin' special." Eliot wasn't entierly great at this whole providing verbal comfort. Physical gestures and cooking a good meal were more his style.