<human>: Can you summarize the given text in a few sentences?

I am a junior in highschool and I recently broke up with my bestfriends older sister (18F) about 4 months ago. After the breakup, my bestfriend ((17F) her younger sister) and I started to get really close. It went to hanging out durring lunch hour to going on movie dates to cuddling watching T.V. I really like this girl even tho I dated her sister (for a month). We always say "I love you" back and forth. But when she says it she means it as a bestfriend way. Now when I say it, I say it like she means the world to me. I just dont know what the next move should be. Anyone out there caring to help?
<bot>: I love my Ex's sister(17F) that I spend more time than anyone else with. I dont know what the next move should be.