Know one but the accuser knows exactly what this guy said and until I know the exact verbiage I say he’s a slime ball for tossing sexual innuendos around the work place under the guise of a serious topic. A topic that doesn’t get casually bantered about the work place.
So, by your own admission you don't know what was said, but you assume he acted like a "slime ball" without any evidence.
I can think of a couple scenarios where simply broaching the topic, even with carefully chosen language, could be misconstrued. A lot of people think "surrogacy" implies sexual intercourse with the surrogate. That is not going to result in his wife's embryo being implanted in the surrogate.
I reserve judgement (condemnation) until I see the evidence of impropriety.