I am sure there is a reason... He knows that Suman and Shravan feel for each other and want to bring out the truth. He went to extreme so he can get out this marriage joke jhangat. Otherwise he would be stuck with one long faced unhappy wife that no one deserves
If this is the way to break marriage then how is he any better than Sumon? Sumon needed to two things. One tell him that she does love someone but it was one sided (as shravan never confessed and they were never in a relationship) and second that she needs time. Second one she did last night. She asked for time. In arrange marriages the feeling of love might not come overnight. Just because Adi loved her at first sight doesn't mean she has to feel the same way.
And you said Adi must have a reason to get physical (he was trying to pull her off the bed forcefully). Nothing should give a guy to get that violent with a girl he intends to marry. If we reason this kind of behavior we are actually encouraging domestic violence.
Sumon hid her past if this bothers him too much then tell her off and call off the wedding. Breaking a relation on the day if the event is insulting enough without being violent.
Just my opinion.