So is "free love" a Christian possibility? Epiphanes thought so, and in arguing against him, Clement cited the adultery regulations of the Decalogue—not porneia. At this point, I could see an argument to be made for sexual restriction between religions, i.e. Christians not sleeping with members of other faiths—though I think there's also an argument against that.

Between Christians I'm not sure how sexual regulations could be scriptural. All Christians are "one body" (1 Cor 12:27 etc), so you'd be left arguing that members of the body shouldn't 'touch' the body. Awkward. Note Acts 4:32: “No one claimed that any of their possessions was their own, but they shared everything they had.”

Now almost immediately that was being revised in actual practice. The Letter to Diognetus, c. 127 A.D., describes how Christians live: “They have a common table, but not a common bed.”

Tertullian later adds a similar note in the 3rd century: “All things are without distinction among us except wives.”

But Acts 4:32 doesn't have that qualifier. One would have to say it's silently present, otherwise it becomes possible to 'share' everything, including oneself.