@ladyloverrori89: Scathach and Tamamo didn't expect that Mordred had a crush on Jeanne and would give Valentine's chocolate to her in the middle of them having sex and got near-violently jealous, then Mordred revealed that she had chocolate for both of the other girls anyway, then Mordred became the center of a thank-you orgy before being presented with a chocolate mock-up of Caliburn in the stone, prompting Mordred to reenact Artoria's drawing of Caliburn to earn the right to kingship, with the cherry on top being that Jeanne cosplays as Artoria to role-play said King of Knights acknowledging Mordred's right to rule, Scathach is apparently cosplaying as Morgan le Fay, and Tamamo... I think she's cosplaying as Merlin.
@gweanakjakarta: I don't think Artoria ever had a problem acknowledging that Mordred was her son, it's just that she considered Mordred's flaws to outweigh whatever "right" she believed she had to succeeding Artoria as King of Britain through either blood relation or the many great deeds that she managed to perform.