Those asking for old saves. Lily's entire story line has been redone, so I'd recommend that you start over and just do her quest line by itself. No other quests need to be completed as a prerequisite. Bulldoze through a few days Maxing all your stats and then just do her quest outright.
***Also be warned!*** The new H-Scenes are not in the Gallery section yet. So in order to see them again you'll have to go through the quest line another time. There is one scene with lily that will freeze, you'll get the jist of it before it freezes so just press Tab and it will skip passed the rest. Save often!