Yes didis
Janam dene se kisi Bache ke saath lagav hona saroori nahi he. Even if we say all children are equal for the parents. Jo Bache hamare saath nazaron ka saamne pale bade ho unse laagav zyaada hotha he. Malhar has been away from his father right from childhood. They really don't know each other and their charechtes.
But sarthak and malhar know each other better. They very day he came he understood malhars unsaid feeling for kallu. Why he wanted dangal. That coffee scene he understood that malhar awaits kallu in balcony. And every nuances of malhar Kaka seems to understand them well. Which madhav fails to do .
So does malhar. Before anyone else he knew kakas love for maayi .even ketki time he said I know that you love maayi I know. We are like friend he said . Hus eye always noticed kakas feeling.That is beacuse they have spent years togather. He immediately believed kaka deed wasn't intentional but for madhav he will be like will he or won't he he can't be sure at all.
I think the groom's family knows them or something as per the segment we can see that baapji didn't come to meet them first only when malhar came he came out. Even then he was a kindoff hiding his face with his hands gestures and malhar also seemed to have noticed something fishy.