The things I love most about every fictional couple are actually small, details that not many people would immediatelly spot. Those details don't add that much to the relationship (sometimes nothing), non-shippers sometimes don't see them, but shippers love them. Here are a few such things about Lucius/Lily:
1) Letter 'L'
Yes, well, this one is obvious. Lily and Lucius are both names starting with the letter 'L'.
2) Eye colour
Lily has green eyes while Lucius' are gray. Those would be the colours of Slytherin. While Lucius was a Slytherin, Slughorn, the head of that house, appreciated Lily and probably regreted that she wasn't in his house.
3) Slughorn's favourites
The last point brings us to this one. The two of them were Slughorn's favourites. We found out about it from Slughorn (about Lily) and Draco (about Lucius) in HBP. Both of them were members of Slughorn's elite Slug club.
4) Snape
The story's most complex character had only two friends, Lucius and Lily. Lily considered Snape a friend even though he joined Slytherin. They parted in later years because he became too friendly with a few dark wizards in Slytherin, but funnily Lily didn't mind his friendship with Lucius (one which was obvious since Sirius who cared even less about Snape noticed it, he called Snape Lucius' 'lapdog'). She was the reason Snape turned against Voldemort. Lucius, on the other hand, never cared about Snape's heritage and always spoke well of Snape in the MoM (according to Umbridge). In HBP, Narcissa refers to Snape as Lucius 'old friend' and asks him to help Draco with the task Voldemort gave him. Snape, of course, agreed.
1) Letter 'L'
Yes, well, this one is obvious. Lily and Lucius are both names starting with the letter 'L'.
2) Eye colour
Lily has green eyes while Lucius' are gray. Those would be the colours of Slytherin. While Lucius was a Slytherin, Slughorn, the head of that house, appreciated Lily and probably regreted that she wasn't in his house.
3) Slughorn's favourites
The last point brings us to this one. The two of them were Slughorn's favourites. We found out about it from Slughorn (about Lily) and Draco (about Lucius) in HBP. Both of them were members of Slughorn's elite Slug club.
4) Snape
The story's most complex character had only two friends, Lucius and Lily. Lily considered Snape a friend even though he joined Slytherin. They parted in later years because he became too friendly with a few dark wizards in Slytherin, but funnily Lily didn't mind his friendship with Lucius (one which was obvious since Sirius who cared even less about Snape noticed it, he called Snape Lucius' 'lapdog'). She was the reason Snape turned against Voldemort. Lucius, on the other hand, never cared about Snape's heritage and always spoke well of Snape in the MoM (according to Umbridge). In HBP, Narcissa refers to Snape as Lucius 'old friend' and asks him to help Draco with the task Voldemort gave him. Snape, of course, agreed.