First off, he would have known it's Riya's house, he's been there before.
And, last I remember, Riya's house got no storeys therefore, no stairs, aur hamara Shivam babu was seen going up the stairs.
So once again, a hit-and-miss. I am growing very eager to see how these 2 are gonna end up getting married to each other. (of course, not before a loadful of drama in the family, especially from shashikala aur unki suputri)
ps: loving the show so far..