Guilt

Well everyone easily blaming abhi easily believe aliya, but i wonder guilt plays major role in aliya case so everyone not only abhi believe her. We accept or not purab and bulbul love plays major role aliya character change.

I think abhi (including purab, daadi, pragya and others also)guilt over himself for aliya change (because he was the one who fix marriage with purab) that why he easily believe whatever aliya said is true.