I dont understand why Jeanne said, 'Now I understand why you were in a threesome with Alice and Julie.' What did she mean?
I didnt quite get the threeway realationship. Did Julie want to be in it? Did Ismael? Both didnt seemed to pleased about it. Who had the idea?
It was Julie's idea. During the conversation with her mother in the kitchen, her mother asked her, whose idea it was, and Julie said it was hers.
None of the three were happy about how things turned out to be. Alice wasn't getting the love from any of them (which I think she secretly wanted, despite of her mocking and saying, she wasn't in love). Ismaël was frustrated and a bit jealous because Alice had claimed she didn't sleep with men any more and would only practice "non-sex" (it was in the scene when the women were discussing the pill - Ismaël asked Alice why she'd use contraceptives at all since she said she wouldn't sleep with men anymore - but Julie told her mother that Alice was meant for both of them and the three of them sometimes did it all together). And Julie was also jealous when she sniffed Alice on Ismaël's hand (during the song "Je n'aime que toi") and frustrated because Ismaël wouldn't make up his mind and fully commit to her. The underlying conflict between Julie and Ismaël was that she wanted a child, and he didn't. Jeanne mentioned it during the row with Ismaël, only that Jeanne thought it was because Ismaël was gay. That wasn't the reason and clearly, he was not gay.
In the press kit interview Louis Garrel said:
In the screenplay, the couple argued because he didnʼt want a child. This aspect is less present in the film but I kept that guilt in mind to play my character (...) I donʼt think that itʼs a coincidence that Ismaël then meets a boy. Ismaël falls in love with someone who cannot have a child someone totally different from Julie who will not encroach upon his love with her.
Source: http://www.festival-cannes.com/assets/Image/Direct/022199.pdf