It's not the fact that he'll find out.
Sadhana should have told him. He deserves to know. I love Sadhana, but she really irritates me when she keeps secrets especially ones that others deserve to know.
Aalekh is in stress.. this could have brought him a few moments of happiness. He deserves as much. Not only that, he's also worried about her health.
Disappointed in Sadhana today.
So agree with you. Even if she is thinking about others happiness then also hiding this news from Alekh makes no sense at all. This is so crazy. Hopefully she shares this news with Alekh in tomorrow's episode.