love-in  {n.},  {slang},  {informal}
A festival or occasion to celebrate life, human sensuality, the beauty of nature, human sexuality, and universal love; affairs so conceived by some frequently deteriorate into obscenity and drug using sessions in parody of their stated purpose.
The hippies gathered for a big love-in in the Halght-Ashbury district of San Francisco.
Categories: human love {informal} {n.} {slang}