I vaguely remember seeing this movie sometime in the mid-2000s, though it may have been a 1990s-early 2000s movie from what I remember of the screen quality.
There’s this woman who returns (with her fiance/boyfriend?) to a childhood place, where there’s a lighthouse home(?) overlooking the sea. And she’s initially scared of her former childhood friend who lives there, because her mother claimed that when they were children, he tried to seal a pact with her using a knife and their own blood.
But later on in the movie, it turned out that her mother lied to her – she had forcibly separated her from her childhood friend after she saw them seal a promise… with a kiss. And then somehow, she had manipulated her daughter into repressing that memory (which at the time seemed a bit odd to me, did she hire a psychologist to do that?).
Also, her fiance/boyfriend turns out to be a complete douchebag, as he had cheated on her with one of her friends – that friend ended up pregnant, not to mention remorseful (as she has a boyfriend of her own whom she loves very much, especially after seeing how sweet he is to her), and so the woman’s friend tries to hide this secret. However, it gets revealed in the climax, and the woman’s childhood-friend-now-turned-lover beats up the douchey fiance/boyfriend and has him thrown out. In the end, the woman’s friend ends up staying with her own boyfriend, who accepts the unborn child. And the two childhood friends of course end up together.