As gayu said if malhar's reason behind hiding kallu's truth from avini is cuz of her father that he would do some to kalyani if he knows the truth.
Then maybe as ahir made her pregnant and left, and he belongs to rane family maybe her father blackmailed or forced malhar to marry avni, or pretend to be her husband.
This may also mean that avni as an individual maybe a good person. Is she gets to know kallu and malhar's truth she might help them get back together. Beech neech mein uska father taang gusane ki koshis tho karega but ab beti ke aage kisti chalti hai.
Any am saying this again, i hate this avni wala track. Aur yeh kuch new concept tho hai nay. Bahut si serials mein hochuka hai. But good thing here can be that avni maybe a good person. So yeh obstacles create karne ke bajai maybe uski help kare.
Kuch bhi kare, show se jaaye basss...🙏