Sexual Encounter Group (1970)
Alex de Renzy started off his career making documentaries including this one here, which involves a group of people who gather in a house where they feel, smell and touch each other before everyone has sex. I must admit that it's hard to judge this movie because the last two reels are missing their soundtrack so it's impossible to hear what the people are talking about and the truth is that the spoken words were often the best thing going for the picture.
As a documentary this is fairly well-made but there's no question that the subject itself is what really sells this. You'd think that a group of people sitting around sniffing one another would be boring but I thought the people were rather interesting and their laughing and goofing off seemed legit and this "party" just seemed like a good time. The film is all softcore at first and in fact it takes quite a while before we see any actual nudity. The final fifteen-minutes is when the group begin to have sex and there's some hardcore footage, although the film still plays more like a documentary that just some cheap porno.
Again, it's really too bad that the soundtrack is missing for the majority of the movie because this makes it impossible to fully judge. Vinegar Syndrome has replaced the missing soundtrack with music from other de Renzy films. Still, even with the missing soundtrack, I found this here to be rather entertaining.