it's a harem situation idiot. No matter which girl Lelouch likes it will be forced.
"oh shirley I totally fucked up your life and being near you is a massive guilt trip, but I still love you durr"
"oh c.c I was never once attracted to you and our relationship is entirely business but now that we have got to the last episode I gotta say I like you to satisfy shippers and sell more dvds"
"oh kallen, you disappeared of the radar in the second half of season 1 and now your catch up development feels a bit forced but hey I like your tits, let's fuck"