accusation without consent from a very young age, lost generation

Hi,

I’m 19 (M) and this girl (F) is 17.
We had a period of flirting which lasted 1 month and then we concluded. Everything was going well until the day it wasn’t going well anymore, so we took our time to talk and we decided to stop (she didn’t want to) but I couldn’t take the hassle every day anymore.
so I took all my things back from her and the same for her (with respect of course).

we live not far away, so she knows a few people at my high school.

One afternoon I was leaving school, when a guy came up to me and said, this is the first and last time you’re forcing a girl to do things, so I explain to him that he must be making a mistake and that I’ve never done that.

At the moment I didn’t really realize what had just happened, so I decided to go and look on the networks, and this boy and this girl (my ex) are friends whereas before they weren’t?

while I was super kind to this girl, and I always had respect whether for that or other things..

What should I understand after all this?

from an outside point of view, could you help me, thank you!