Mr Kawczynski revealed how he had travelled back to Shrewsbury from Parliament, with some big news for his constituents.
"It was news I was scared to tell, even to my closest supporters in the local Conservative Association – so much so that I was quietly praying the train would break down so I would not have to impart it. The news was that I was now in a same sex relationship."
The MP for Shrewsbury and Atcham will this year enter into a civil partnership with his long-term partner Fernando. And he says the supportive reaction he got from his constituency party six years ago will stay with him all his life.
"Full of apprehension, I looked up at the faces of the people I had spoken to, 50 of the most senior members of my local party and awaited their reaction," he recalls.
"Almost immediately, a gentleman in the front row stood up and said, 'I think that’s marvellous news, well done' and began clapping.
"He was soon followed by the rest of the room who afterwards came up to me with hugs, well-wishes, and offers of drinks at the bar.
"The kindness and humanity of people on occasions like this restore your confidence in our society and the warmth I felt from my association members that night will stay with me forever."
While most of the media attention on Wednesday's proceedings in the House of Commons focused on Brexit, Mr Kawczynski was leading a much more low-key debate. In his first Westminster Hall debate since entering Parliament in 2005, Mr Kawczynski asked fellow MPs to consider what could be done to in schools to encourage the acceptance of lesbian, gay, bisexual and transgender people in society.
He says it was the reports about parents in Birmingham protesting against LGBT teaching in schools that made him decide that the time was now right to hold the debate.
"As someone who came out in their 40s, I never want young people today to have any of the reservations, concerns or fears that I had," he says.
"I want them to be proud and open with their families and friends about who they are. No child should feel that they are sinful or wrong for being gay."
Mr Kawczynski, who is 47, had been divorced for two years and had a young daughter when he made the announcement to his constituency party. He says he felt extremely lucky to have enjoyed so much support from his party colleagues, and believes that people in public life had a duty to speak up for those who are not in such a fortunate position.
"This debate is so important because it will showcase both Parliament’s view and that of the wider country," he says.
"It will demonstrate that we are staunch defenders of LGBT rights and will work diligently to create a Britain where telling someone you are LGBT is no more of a surprise than telling them you are left handed."
He says another reason for him deciding to call the debate was the story about a young friend of his parliamentary researcher, who had resorting to self-harm over his fears about revealing his sexuality.
"Whilst I was delighted to hear that my researcher had reacted in the way we’d all hope – by embracing his friend and not caring in the slightest – I was still saddened to hear that this young man felt so fearful and apprehensive about coming out, even to a close friend," he says.
Talking about the demonstrations outside Anderton Park Primary School in Birmingham, Mr Kawczynski speaks of his sadness at the polarisation of opinion on both sides, and hopes that a middle-ground can be found.
He appeals to the humanity of the protesters, asking them to try to see things from the opposite point of view.
"I would would ask them to try to understand the importance of giving young people confidence, of making them feel accepted, and allowing people to be free to be who they are, regardless of their sexuality," he says.
Mr Kawczynski says his own upbringing, from a strict Polish Catholic family, made it difficult for him to accept his sexuality, and says there are members of his extended family in Poland who no longer speak to him.
Mr Kawczynski will 'marry' Brazilian Fernando in a ceremony at the House of Commons on November 9.
"It may be that by then we will be in the middle of a General Election campaign and it will be a case of rushing back to Westminster to get married, and then getting straight back on the campaign trail," he says.
"But nothing is going to disrupt it, election or no election, the ceremony will take place on November 9."
He adds that the decision to enter into a civil partnership rather than the full marriage – same-sex marriages were introduced by David Cameron's government in 2014 – was a personal one he had agreed with Fernando.
He says there are still many countries in the world where homosexuality is still a crime, and says it is important that Britain sets an example for other nations to follow.
"Britain is a nation of tolerance, of respect, of freedom, and we must hold these values high as a beacon for the rest of the world to follow," he says.
"It is of huge importance that we do set this example because while we are fortunate enough to live in Britain, there are many nations which do not share this view and do not share our values of liberty and tolerance.
"There are still at least six countries around the world enforcing a death penalty for homosexual acts, and many more handing down harsh prison sentences for nothing more than the ‘crime’ of being in love.
"The only way we can combat this is to prove that there is another way, a better way – having this education in our schools can only help us to promote this aim and to champion LGBT rights worldwide."