Now believed to be leaving his wife of 15 years over the affair, the former UK health secretary has pleaded for “privacy”.
However, given his behaviour there are still serious questions about his conduct that must be answered, irrespective of his resignation.
How long has his relationship with Ms Coladangelo been going on?
Mr Hancock and Ms Coladangelo have been friends since they worked together on student radio while at Oxford University.
The former lobbyist joined as as an aide in March last year, before moving on to the Department of Health and Social Care (DHSC) director role – a job paying £15,000 a year for 15 to 20 days' work a year.
Given reports the pair now plan to be in a relationship together, there are questions over the appointment process, and whether Mr Hancock failed to declare the relationship before her appointment.
A government spokesman has insisted the appointment was "made in the usual way" and "followed correct procedure".
Also, until May 17 people were barred from hugging loved ones, suggesting it was not an isolated breach of the regulations.
Why did Ms Coladangelo get a parliamentary pass?
Ms Coladangelo got a parliamentary pass to Parliament last year after having it sponsored by junior health minister Lord Bethell.
Despite this, it is believed Ms Coladangelo never actually worked for him.
The Labour party’s Anneliese Dodds has now written to the House of Lords' commissioner for standards demanding an investigation.
Why didn’t the Prime Minister sack him?
Mr Hancock resigned on Saturday evening after a meeting with the Prime Minister.
Despite breaching the rules he enforced across the country, and doing so during office hours, Mr Johnson failed to sack the former health secretary.
Downing Street had insisted “the matter was closed”, only to see Mr Hancock resign amid growing pressure.
As per home secretary Priti Patel’s bullying report and Mr Hancock’s earlier failure not to declare a stake in an NHS supplier show, breaching the rules no longer appears to have consequences.
For a leader who once removed the whip from rebels who didn't support him on Brexit, the Prime Minister now seems either weak or simply willing to ignore the rules when it suits him.
The ministerial code states that ministers should be "professional in all their dealings" and have "proper and appropriate" relationships with colleagues.
How did the CCTV footage get out?
It is unclear how the footage of Mr Hancock kissing the married mother-of-three was leaked, with MPs now concerned of a serious security breach.
Justice secretary Robert Buckland said on Monday morning CCTV should not "snoop" on ministers, and warned it could end up in the "wrong hands, with states that wish us ill or wish the United Kingdom ill".
Did Mr Hancock break the email rules?
Mr Hancock also used private emails that bypassed disclosure rules when doing government business.
New exchanges have emerged showing the former health secretary had personally referred a former neighbour wanting an NHS contract.