Unable to digest it all he might leave the country and go away for few days(remember he left for London when Geet said she will find another job fortunately his flight got cancelled)It is not that he would not want to support Geet but he feels that Geet still loves the other Guy and is unable to take it.
On the other hand Geet thinks that after knowing the truth Maan does not want to face her and so she decides to leave the outhouse.
OMG AND THE SAD MOMENTS COULD GO ON UNTIL THE FULL TRUTH IS NOT FOUND OUT!!!!!!!!!!!!!!!!!
I know none of u and even me would not want such a thing. But it is just my point of view that even this could happen just to stretch the story for a few more episodes by the CVs