short version is better without Kathy Redfern's midsection
Too bad that the song on a 7" 45 RPM single had Kathy Redfern's annoying be-quiet-big-boys-don't-cry junk ruining in midsong that 10cc's record label, Mercury had no time to omit, plus it's too bad that the repeated first verse was omitted too abruptly. I will call that song very heartfelt and bittersweet that touches my heart, because it's mainly all about marriage relationship falling out of favor. Besides it's very touching.
I made a comment about that song on YouTube and said:
It's too bad that in 1975 British band 10cc might have taken a break from having a wacky sense of humor and started concentrating on a serious relevant version of the bittersweet heartbreaking ballad, "I'm Not In Love", minus Kathy Redfern's self-parody and believe me it is 10 times better than the epic 6-minute version of that song with her part added.