Former LSE student and county-level tennis player Jesse McDonald, 25, stabbed to death Naomi Hersi, 36, after contacting her through dating website Fabswingers.com.
The sentencing comes days after a jury found McDonald guilty of the “cold and calculating” murder, in which he drugged and stabbed the hospitality worker to death with a knife and a broken bottle at the hotel close to where he was living.
The defendant then spun a web of lies to his mother, who lived in Haywards Heath in Sussex, and hid in the hotel room as he waited for his 18-year-old girlfriend Natalia Darkowska to help clean up, jurors were told.
But the plan to dispose of the body was scuppered when police found the victim lying half-naked, partly covered by a rug on the small bathroom floor.
McDonald, a former London School of Economics undergraduate, denied murder and claimed he acted in self-defence.
He and Darkowska, from Trowbridge in Wiltshire, both denied perverting the course of justice following the killing in March.
The couple wept and embraced in the dock as they were found guilty of the charges following a trial at the Old Bailey in October.
McDonald was jailed for life with a minimum term of 20 years for murder with 30 months concurrent for the second offence.
Judge Mark Dennis QC rejected the defendant’s claims he was drugged, raped and held in a “death grip” by the victim.
He pointed out his capacity for mixing up fact and fiction, saying McDonald had a complete disregard for anyone but himself.
The judge said: “This was a dreadful assault on someone who it would appear will have been in no position to respond to an attack by you using a weapon. He was overwhelmed by the nature of your violence.”
Earlier in mitigation, Michael Turner QC told how McDonald had a “promising academic career” which was cut short when his drink was spiked in 2014.
The defendant’s parents, who attended the trial, sent a letter to the judge expressing their sorrow.
In a victim impact statement, Ms Hersi’s family described her as a “sweet and trusting” person who was “funny and carefree”.
Her sister Amina, a hospital doctor, was the first to hear the news of her death while at work.
Father Mohamed Duale described the murder as the “ultimate injustice”.
He said: “Our lives will never be the same. The grief has swallowed us up. It’s consumed us. Maybe one day it will not be so painful but the violence of his death haunts us.”
The trial heard how McDonald, who grew up in West Sussex, did well in school and played tennis at county level but turned to dealing drugs and trading in Bitcoins after dropping out of the London School of Economics.
On 12 March, he contacted Ms Hersi within 45 minutes of arriving back at the Heathrow Palace Hotel in Hounslow from visiting his girlfriend.
He drove his BMW to the victim’s home in Mill Hill, north-west London, where he stayed for three days before they both went back to the small hotel room in Hounslow.
Throughout the period, McDonald is said to have ignored his girlfriend’s increasingly frequent attempts to get in touch with him.
But on Friday 16 March, he sent her a message which said: “Baby I been a f****** idiot.”
Another read: “I love u so much. Not cheated x. Got addicted to a nasty drug I had never met before.”
He then told her he had “got a big drug dealer” lying across his floor, adding “won’t wake up ... massive black guy”.
While the defendants were cleaning up, McDonald phoned his mother and claimed he had been chained up for days, drugged with GHB and repeatedly raped.
McDonald alleged he had stabbed Ms Hersi up to 40 times in a frenzy, believing she was about to smother him with a pillow.
His mother, from Haywards Heath, phoned the police after the conversation with her son.
The defendant also offered his landlord a designer watch if he cleared up his room before confessing he had killed someone, jurors heard.
Some 10 minutes after his last call, police arrived at the property and found Ms Hersi’s body and the murder weapon.
The defendants were tracked down to a hotel in Teddington and arrested.
During his police interview, McDonald continued to claim he had been bound and raped.
Giving evidence, the Brighton-born defendant said he had contacted Ms Hersi online “because I’m a complete idiot”.
He made no reaction as he was sent down.
Darkowska will be sentenced at a later date.
PA contributed to this report