Apparently Christian (character) knew about Mallory's doubts about her forthcoming wedding, and (SPOILERS) about her lover(?) Ella. How? It's not even hinted at in the film. And where did he come from, in a desertic environment. Mallory should have spotted him from far ahead.
shareI can't remember for sure -- I'll have to check -- but I thought she told him about her sister when she was driving him? He said he was hiking. He knew about her doubts because Mallory wasn't wearing her ring, and she was reluctant to let him out of the car/ offered to stay at the hotel with him.
shareI thought the same thing, he seemed to know a lot about her and it didn't seem like she told him. I thought they were going somewhere with that and then nothing.
shareYou missed a lot. Ella is her sister. She calls her "sister" when she answers the phone, and they talk about her getting plane tickets for Mallory's wedding, and also about Ella's dating and "promiscuity." She refers to her fiancé "Brad" many times. She gets a voice mail from Brad about cancelling the honeymoon. She finds fliers from strip clubs and says to herself "*beep* you, Brad."
When she talks to Christian in the car, she talks about Ella and about Brad and the wedding.
Also, when she tells the story about losing her virginity, Christian says "haha you can't fool me I know that's your sister Ella's story."