If you care about her then nothing. She told you the truth and you should appreciate her honesty, even if it was belated.
tell his girlfriend
yes. but they only kissed and never slept together Yes then he split with Olivia and then him and Miss England were together but now they have reportedly split
No. Why would you want to associate with someone who treated you so shabbily and who obviously has such low standards of conduct? She is not someone you could ever trust.
well yes you slept together!
yes
I would ask her about it and if she asks where you heard it from, tell her the truth. The best thing that keeps a relationship together is honesty.
they've definetly kissed but never slept together
I'm guessing they are implying you two should have had sex at some point or another.
don't tell them! Unless asked
they had sex!!!!
yes they slept together
The only way to know for sure is to ask her.