I think Camille.....
I think Camille simply wanted to leave Paul cause she find a rich man(Jerry)who was interested in her but she couldn' t openly tell that to his husband so she find the excuse that she despise him and doesn' t love him anymore because he left her alone in the car with Jerry.
I think the simple truth is that she thought " Uhm, a millionaire is interested in me, that' s mean no more economical problem, an easy life, nice villas, what a great opportunity I must catch it!"
Camille didn' t refuse Jerry attentions, she kissed him, at the end she has gone away with him and when Jerry said to her "stay with me I will care about you" she doesn' t say no but she said "we will talk about it".
Camille and Paul had economical problems, her husband even didn' t have the money for paying the flat, she simple chose the easy life, also other women do the same thing in the real life, they leave their husband or fiancé because they find a richer man.