Love Won't Let Me Wait was written by Vinnie Barrett (real name: Gwendolyn Woolfolk) and MFSB lead guitarist Bobby Eli. The uncredited vocalist who did the moans and groans is Barbara Ingram. She sang background vocals on albums by Billy Paul, Evelyn King, Claudja Barry, Lou Rawls, Marvin Gaye, Stevie Wonder, Sister Sledge, the Trammps, the Spinners and many others.
Here is today's entry in the "What were they thinking???" contest. The Lettermen, best known for When I Fall In Love, Come Back Silly Girl, The Way You Look Tonight and Goin' Out Of My Head/Can't Take My Eyes Off You, recorded Love Won't Let Me Wait for their August 1975 album The Time Is Right. At least nobody moans and groans in this one: