Love(2015)

You're referring to the documentary film "Love" (2015) directed by Gaspar Noé!

Here's a helpful report on the film:

"Love" is a French drama film that follows the story of a young couple, Emma (Emmanuelle Devos) and Isaac (Vincent Cassel), as they navigate the complexities of their relationship. The film explores their intense and often tumultuous romance, which is put to the test when Isaac's past and his relationships with other women come to light. Love(2015)