Pre-Marital Sex Arguments

I am not very familiar with progressive Christianity, but I am looking for Christian theological and biblical arguments that are being used in support of pre-marital sex. Obviously there are tons of arguments against pre-marital sex from more conservative and fundamentalist Christian theologians and biblical scholars, but I'm looking for the other side. Could ya'll point me in the direction of some sources? These can be scholarly (progressive theologians or biblical scholars), clergy, denominational statements, or laity/bloggers. The more variety the better even! Thanks!