If we look at Indian historical sources carefully, then Ancient and Medieval Indians, atleast the Aristocracy and the Business class were pretty open about Sexual Practices. Kamasutra and the Temple at Khajuraho is a good example of that. Even during the medieval period in many, both Hindu and Muslim aristocracies, there was an open sexual life.
Fast forward to the current day, Indians are pretty hesitant to talk about topics related to sex and sexuality. I am not very good at biology so my mother explains biology to me. She explains the other topics without any hestitation but when it came to Sexual Reproduction in Animals, I could tell that she was pretty uncomfortable with it. How did it happen? Is it something new or was it simply present only amongst the aristocracy and normal people were pretty much the same as they are now today?
/u/Kelpie-cat has previously answered Why do most ancient Indian structures have so much nudity despite being so conservative in modern days? which has a similar premise.
I hope someone else can offer you an original answer.