It is difficult to say with any certainty exactly what the sexual attitude of ancient India was. It does, however, seem certain that family values were of high importance and marriage was a sacred institution, one that well-adjusted men and women were expected to embrace as the appropriate setting for sexual indulgence.
There is still much reason to believe that sex without commitment, and especially without regard for spiritual considerations, is less than ideal. Kama-sutra no doubt explores sexual pleasure in some depth, but the mere presence of this sutra in ancient Indian society does not mean that the society itself was sexually promiscuous. Neither does it mean that everyone followed the practices outlined in Kama-sutra. Royalty more likely followed Kama-sutra practices than ordinary people.
I do not mean to say that you have implied that a sexually promiscuous society is one that has a healthy attitude about sex. And in some respects I do feel that Indian society today could have a healthier attitude towards sex, and that its thinking about sex has been, in some respects, more influenced by Victorian standards than by its own ancient spiritual culture.
Submit questions about Hinduism to Swami Tripurari by firstname.lastname@example.org or by visiting www.swami.org/sanga.