A detective inspector slapped a female police officer on the bottom while calling her a "naughty girl" for making her own cup of tea, a misconduct hearing has heard.
Detective Inspector Matt Banks is accused of hitting the woman at work on January 3 this year.
The Kent Police officer is accused of gross misconduct by breaching the standards of professional behaviour of authority, respect and courtesy, equality and diversity and discreditable conduct.
Mr Banks admitted his actions and accepted it amounted to misconduct, but denied it was gross misconduct.
Tuesday's hearing heard Mr Banks had made tea for colleagues when he saw the woman making her own tea after she was inadvertently missed from the round.
Aaron Rathmell represented Kent Police.
He said: "He was making a round of tea, [the woman] was inadvertently left out.
"There was banter between them as he did so. The atmosphere, the context of the exchange was good-humoured at that point."
The panel was told Mr Banks then walked over and slapped the woman on the bottom, telling her words to the effect of "just leave it, you naughty girl, I'll do it".
The woman gave evidence and said she "froze in place".
She said: "It was a hard slap, it was a slap on the bottom which was of force, loud enough to hear it, to feel it. It hurt and made me jump."
Nick Yeo, representing Mr Banks, suggested he had described the woman as a "cheeky girl" rather than naughty, but this was not accepted by her.
The woman told the panel he said "just leave it, you naughty girl, I'll do it" but accepted the phrases may have been in a different order.
Mr Banks is also accused of trying to discourage the woman from reporting his actions, telling her "what I did didn't happen, right" shortly after.
Mr Rathmell said: "He was subtly seeking an understanding whereby both him and [the woman] and potentially others would pretend they did not see what just happened."
Mr Yeo disputed the wording of the comment and said it was made "through embarrassment and had no malign purpose".
The hearing was told the slap did not have a sexual motive and was not done to gratify Mr Banks.
A witness, referred to as DS B, described it as "like a ticking off slap, not a sexual slap".
The woman said the incident had impacted her trust and feeling of security at work.
She said: "This is 2020, this isn't the 1970s. I never would have expected that to happen to myself or anyone else.
"I love my job. I come to work, I feel safe. No matter what else is going on in my life... I always come to work and feel happy and comfortable around people that are probably closer than some of my family members."
She added: "I was embarrassed to think that somebody would think that was acceptable, I've never given that impression to anybody in my work or social life that would be acceptable behaviour."
After the woman had finished her evidence, Mr Yeo said on behalf of Mr Banks: "He wishes to apologise to you.
"He describes himself as being mortified, embarrassed and disappointed and he accepts that he has let you, himself, his family and Kent Police down."
The hearing continues.