The subtle come on (1970)

It isn't easy being the new girl in the office - especially when you're particularly clumsy and stupid. Brandy accidentally bumps the accountant and knocks salad dressing and a cherry tomato into her cleavage. Without skipping a beat, Brandy offers to help her clean up and proceeds to lick the dressing off the accountant's cleavage. It's a good thing their office is so quiet and lightly staffed so they could make all the noise they wanted while having passionate sex in the accountant's cubicle.