Tinami, I think maybe in an idealized world, sex wouldn't be THAT big of a deal and people can have bad sexual experiences (not sexual assault or rape but just bad sex or sex they didn't enjoy) and relationships and can end it and all parties involved can act mature and move on even if that person's sexual partner was their teacher, boss, coach, some sort of supervisor, had some position of power over them. I get how your idea that sex can be something like a handshake being appealing and something one can easily get over. However, it almost never works out that way and experience and a huge number of case studies have shown than when there are unequal power imbalances, especially with an age difference where one party seriously lacks life experience and perspective and depends on the other older partner for judgment and is learning from them, there's always some sort of coercion, manipulation, and even consequences (psychological and tangible) if it goes sour.
First of all, the example i keep referring to is "younger person/student/employee initiates relationship with older person/teacher/boss", so if there is "power imbalance" it is initially on the side of the one being pursued by the one with "less power".
Second, is that i don't understand what is the damage if two people, connected by work/school/sports, spend a night together?
Let's take the most feared case scenario: lets say a 40-year old man in power, a boss/teacher/coach (unmarried, pls note, i am excluding such right if person is married, since marriage is a contract and one has no right to break it by cheating), flirts and seduces (in a nice way, with flowers, gifts, compliments, NO coercion or violence of course) a younger woman 20-year old. As he pursues her, she starts to like him and seeing various charms of that man and perhaps benefits, personal, physical, intellectual (learning from a wiser person).... And yes, she comes to this state of mind as a result of his actions, but on her own free will. And then they spend a night together. And the he dumps her, or she dumps him.... and it does not affect their work day the next morning. Just ha-ha... that was a mistake lets not talk about it... Or even if she fell in love with him, and he is not interested..
Tell me, WHAT exactly has she lost during that night when they were engaged in mutually enjoyable activity? an arm? a leg? a piece of meat off her body? did he make her pay for dinner and did not pay her back?..... two adults, had fun in bed, and then no more of it.
If we're concerned with "emotional side" how the employee/student girl would feel when a "powerful man" left her, then let's ask a question when two people meet outside of work or sports, and are also in unequal social or financial position, a wealthy man meets a poor girl at the movies and gets her involved in a relationship and then breaks up?
Is the emotional side of a break up any more or less stronger based on where and how people met?
I am pretty sure that a "sensitive person" would upset over a break up all the same regardless if they met at work or at a rink or at friends' house...
And honestly.... i get a sense lately in this topic, or rather finally starting to understand, the perhaps people think that "sex, which woman gives to a man" is some kind of asset.. and if the "seduces her" then he is taking something from her. That a result of a seduction (of a woman by a man) is not viewed as "oh great! they agreed on having fun in bed", but rather "she giving herself to him as a result of his manipulation"...... As if sex is dirty and the woman is potentially losing something... oy, mama mia...
It's not just age differences either. That's why in many big corporations where office romances between adults may happen many of them have adopted policies to minimize any sort of liability. Some strongly discourage dating, some have a disclosure policy where after disclosure if the two dating employees work in the same division one may get moved, many have a strict rule about superiors and supervisors not being allowed to date subordinates, etc. A lot of is about productivity and office morale, but also a lot of it is because those businesses know there is a danger of lawsuits because all of that can lead to real abuses of power even if those sexual relationships started in earnest and were between two adults.
I absolutely agree with cases when the corporation's concern is office environment and productivity. They pay their employees salaries for work, not other activities and indirect consequences of such. But what happens in "employees harts and minds" as a result of an affair, is NONE of their business nor should be used as reason for prohibiting such affairs. If two people in the same office hook up, and their work is not affected, whatever they feel, do, experience is no one's affair. The assumption that "if two employees date and later break up then they will not be able to work in the same office/department/project" is not a valid reason for a rule. What is valid is when as a result of a break up two or one of the two employees starts "acting out" and unable to do his/her job - you fire him/her, and that would be fair. But assuming "the worst" is subjective, and not a reason to pass a law.
The social mores were that you protected your kid(s) and your town and let the next town deal with it as they saw fit. 
