What the hell happened in the end? From trying to understand it it sounds like its saying she was just fucking the boyfriend but some other guy too? And why is she creampied? Wasn't he wearing a condom?
The end is the guy got his childhood friend back. She dropped the other guy and began dating the MC. However, the MC says lately, he can't reach her at night, she's talking to someone he doesn't recognize on the phone, and when going down on her a semen-like substance sometimes leaks from her vagina even though MC always fucks her with a condom.
Basically, she's cheating on him during the ending and this is the hook for the eventual NTR sequel.