This happens; of course it does when eligible people are interacting with one another over time. But I have found that workplaces all have their own culture and I am firmly in the camp that ribald jokes, unrestrained swearing and double entendres are not courteous and professional ways for colleagues to interact.
Many will disagree, I'm sure, but that behaviour as a routine cultivates an environment where things can escalate. It's a thin line between a dirty joke and a dirty joke told with an accompanying lewd gesture that makes somebody (man or woman) feel very uncomfortable. Add in questions getting too personal or maybe a shoulder squeeze or grab around the waist and all of a sudden people can feel harassed or assulted. I'd place bets that much of what we're hearing about now has come out of undisciplined workplace environments where things have gotten out of hand.
And FWIW, in over a decade at my job, only one marriage relationship has ever resulted. It was between the "big boss" and a far-junior staff member. Unfortunately they were both married to others at the time and in addition to burning down two families, their brazen antics threw our office into chaos for literally years. Not typical, I'm sure, but a rotten experience for everyone just the same.