I think he will get jealous. Arjun has maya now, he broke ties with saanj for maya. Seeing saanj showing more importance to someone else other than her brother and him will stir something. Honestly from his actions, arjun like both girls. He just never seen. Saanj in a new light because she has always been by his side babying him. When his drunk, his true feelings come out without thinking.
So its possible he will not like the new hot guy. And he will definetly get irratated which will upset maya. I dont think arjun fell out of love with maya. His just pressured right now. He has so many responsiblity compare from before. He just need a vacation far from maya and he will be happy again with her.
And as long as maya doesnt let go or give him space, he will continue to behave like this.
P.s. I think arjun like independent woman, that can take care of themselves.