Abhi gets angry after finding RB's note.His anger to Simi is valid as she didn't told him about it.
Then he know that RB is shifted to 13/24 and again blamed Simi not telling him about this earlier. But he went to RB's house(the old one) without listening Simi.
This is the after effect of hiding anything from near and dear one.If Simi told Abhi about RB's note earlier then he might not blame her for not telling about RB's shifting.