8 year old thinks she had "sex'

Okay parents, this is going to be a bit crazy.I have a very strong willed, opinionated, beautiful 8 year old daughter, we'll call her P. We just moved in the end of September 2019 about 15 mins away from our old house. Our old neighbor was a girl, the same age, named S.P and S use to play together a few times a week and had a handful of sleep overs at S' house. She was always super nice. P and S had little arguments every now and then which was kinda expected from two "alpha" type of girls.Wellllllll... about two weeks ago I was tucking P into bed and she's HYSTERICALLY crying. She said she has a secret and she's scared to tell me. The first thing I think of is something crazy bad and start freaking out, almost in tears! Come to find out she tells me that she and S use to kiss on the lips. I think, okay that's not SO bad. I ask her some questions, she feels better and we move on.Last night, same thing. I tuck her into bed and she starts crying again about ANOTHER secret. Once I calm her down she reveals to me that her and S had SEX. Y'all, she was too scared to even say the word S E X! She spelled it out! So I ask her, what does she think sex means because I doubt that's what happened! She said her and S got ontop of each other, clothed, and made out. I let out the BIGGEST sigh of relief! I tell her that isn't sex and I appreciate her telling me. I kinda left it at that because I'm just so shook. She's 8! I'm not playing the blame game, but I know for sure she doesn't watch these types of things at our house. She said S use to ask her If she wanted to do these things, and she keeps having flash backs about it which is why she gets upset. I tell her she can always come to me to help her fix it but I'm at a lost for words. Idk what to do. Therapy? Just move on? HELP! via /r/Parenting https://ift.tt/2Gnyich