Thanks to some wonderful poster artwork and being billed by Noé the movie already earned itself the "*artporn*" joke. While this isn't true for most of the movie there are indeed some pointless sex scenes to be found.
The story is told from the perspective of Murphy who isn't happy with his current relationship, partially forced on him by an unwanted pregnancy. As he gets a call from his Exes mom worried that she'd done something to herself he starts to reminisce about their old relationship... while doing the opium he got from her "for when he's down". Those segments sometimes carry a Before Sunrise vibe to them but mainly depict what went wrong for the two and sex.
It was sort of nice getting the personal views from the main character (which fit his persona really well while being sort of misogynistic) and Noé adds his directorial flair to many scenes. The music is also really diverse from classic pieces to doing drugs to Salem or a lengthy guitar improv song over a threesome.
While I enjoyed myself in the first half it got rather tedious later on. I don't think we really got into their " love" and some parts of their characteristics were missing; Murphy for instance studies filmmaking (he is an exchange student and came to Paris for this) but this never plays into the plot except for countless movie posters in his room and some dialogue calling 2001 a must-see! Noé also references himself a lot in the movie from naming the MC after his mom, the couples son Gaspar and casting himself as a character called Noé into the movie while calling himself a pedophile...
As for the sex scenes, they're not a big deal mostly and shot well. As the couple gets into their experimental phase however this escalated quite bit with a visit to a swinger club or inviting over a trans only to handle that immaturely. The money shot is obviously also in this in 3D.
The movie had potential but it just doesn't deliver what's needed.