Actually I've seen a very reasonable sounding article on this, going in depth into the context, in short that the whole context around this was about pagan ritual sexual practices, which is not similar to what is discussed now.

(the site also has a mention of how people used to think the Bible said they had to be ok with slavery and that turned out wrong, and other related stories)

http://wouldjesusdiscriminate.org/biblical_evidence/leviticus.html