Ok so Smiley (Rubina Dilaik) is Toasty's friend who moved in to the Chaturvedi household… Tej does not really like Smiley… Toasty then found out that she has brain tumor and she wants Tej and the family to move and on and learn living without her… She tells no one but Dadaji… She leaves the house and then fakes her death and plans strategies in which Smiley and Tej can get closer and Smiley can replace Toasty in his life… Recent track shows Tej being nice to Smiley as she delivered Malthi's baby and Smiley wanting to leave the house… The whole family forces Smiley to stay until the baby's naming ceremony (They have named her Toasty)…. Toasty and everyone now want Tej and Smiley to participate in a Salsa Competition for married couples to bring them closer… However, Tej is adamant that no one can ever take Toasty's place in his life and heart….
Hope this helped! Please feel free to pm me if you need any more details :)