Both men celebrated their birthdays within a fortnight of each other but neither sent greetings to the other.
Dr Mahathir Mohamad turned a golden 90 on July 10 while Najib Razak celebrated his 62nd birthday on July 23.
Their birth dates are a fortnight apart but their political styles are worlds apart and their relationship has hit rock bottom.
The two are probably not into astrology but Dr Mahathir is a Cancer, Najib is a Leo and the two signs are apparently not quite compatible. Both can be moody and dramatic when things do not go their way.
According to the horoscopes, a partnership between them seldom works out as Leo will soon become tired of the constant complaints of Cancer who also wants to play the role of fearless leader.
And if Cancer is not the leader, they expect the leader to be fierce on their behalf. Take all this with a big pinch of salt but it is all written in the stars, as they say.
But astrology aside, Dr Mahathir has been cutting one birthday cake and pulut kuning (celebratory glutinous rice) after another. Turning 90 is really something, especially if one still looks as healthy and good as Dr Mahathir.
On Friday, Berjaya Corp which is owned by Malaysian tycoon Tan Sri Vincent Tan - 14th richest man in Malaysia according to Forbes - hosted its annual Mahathir birthday bash.
The two men go back a long way. Tan has never forgotten that he made his first millions during Dr Mahathir's premiership and celebrating Dr Mahathir's birthday has been a mark of his loyalty and gratitude for the good times.
It was a grand event as usual and it was near midnight by the time Dr Mahathir, dressed in a tuxedo and looking like a handsome James Bond, emerged from the ballroom where the music was still blasting away.
When reporters pressed him about his birthday wish, he flashed his famous ironic smile and said that his wish was for Najib to "retire pleasantly" and to "enjoy his retirement". Naughty, naughty!
Last week, the association of wives of Kedah assemblymen or Bidara marked his birthday as well as that of Dr Siti Hasmah Mohd Ali who turned 89 on July 12.
The birthday couple were in an easy-going mood because Kedah is home ground for them, their son Mukhriz is the chief minister and Dr Mahathir played along as Dr Siti Hasmah fed him a mouthful of pulut kuning.
But make no mistake, this 90-year-old is still going guns blazing at Najib. He has shown no sign of stopping and the fear among Umno politicians is that his attacks have damaged Umno.
A common refrain among many Umno politicians is that they are unsure whether Dr Mahathir is trying to save or destroy Umno. They say that Dr Mahathir claims he is criticising Najib out of his love for Umno but they are simply not feeling the love.
They understand that he wants Najib to resign because of what is happening in 1MDB. But they argue that Dr Mahathir has to accept that the party has chosen to stand by Najib.
Abdullah Ahmad Badawi's swift exit was possible because the party went along with Dr Mahathir. But it is a different story with Najib and they want the various investigations into 1MDB to be completed before passing judgment on their president.
Besides, there have been so many confusing twists and turns in the 1MDB issue that they are no longer sure which is what and where the truth really lies.
They still respect Dr Mahathir as one of the cleverest prime ministers ever but they have doubts about his real motives.
"The way he is doing it, he is not helping Umno. It is as though he wants to destroy our party. Even if he has disagreements, he can do it in a more constructive way," said Kelantan Umno information chief Alwi Che Ahmad.
Umno supreme council member Johari Ghani, who often describes himself as a product of the Mahathir era, has made an impassioned appeal to the former premier.
"I respect Mahathir and what he has done for the country. But I am also pleading to him to be fair and not to undermine the system. He was our PM and he always demanded that we respect and strengthen the system.
"I studied overseas thanks to the government. I came home to a good job and I will always be grateful. But leaders, past and present, must respect the system. There is a high-level investigation on, we cannot pass judgement without clear-cut evidence.
Johari, who is also Titiwangsa MP, pointed out that Dr Mahathir had relied on the same institutions to investigate Anwar and to convict him. He said Dr Mahathir depended on Bank Negara (central bank) to implement the currency controls.
"I am appealing to Mahathir to show the same respect for the system as when he was the PM. Let the special taskforce finish its work. It's not only him, everyone wants an answer to all this, the faster the better," he added.
Alwi, who is also Kok Lanas assemblyman, said that Kelantan Umno met recently to discuss national political issues including 1MDB.
However, he admitted that the 1MDB issue was too complex for most people and that state Umno leaders were more concerned about how to deliver the election promises they had made and about PAS and the new Gerakan Harapan Baru group.
"You come to my constituency, you ask people about 1MDB, you will get a blank look. But ask them about GST, they will have 100 complaints for you," Alwi said.
He said Kelantan Umno is standing by Najib in this current crisis just as it had stood by Dr Mahathir when the latter took on the Malay Rulers and tried to change the Constitution.
"We did not chuck him out, we supported Mahathir through one crisis after another. It is only fair that we do the same for Najib. This is not a football game, changing a prime minister is not like changing players on the field," said Alwi.
Alwi pointed out that Najib is the third prime minister whom Dr Mahathir has tried to remove.
The first victim, said Alwi, was Tunku Abdul Rahman who went from being the "happiest prime minister in the world" to the ex-Prime Minister of Malaysia after the 1969 race riots. Dr Mahathir, then an Umno young Turk, played a leading role in pressuring the Tunku.
But Dr Mahathir also had more than his share of troubles with former prime ministers. He had to face the combined wrath of two predecessors when Tunku and Tun Hussein Onn ganged up with Semangat 46 to campaign against him in the 1990 general election.
The average Umno member is generally unclear about the complexities of the 1MDB issue. What they do know is that it has created a crisis of confidence about the government especially among the urban and thinking class.
Umno has more or less written off the Chinese vote given the way almost every issue is polarised along the race line. Their concern is the young Malay voters. There will be some 5.2 million new voters by the next general election and they are worried about the impact of issues like GST and 1MDB on the new voters.
The ruling coalition is not in the best of shape and they can only take comfort in the fact that Pakatan Rakyat or whatever remains of it is in greater disarray and does not even have a prime minister candidate.
But even those who want Najib to stay on are against the way that certain media have been used to embarrass Dr Mahathir by dredging out scandals that happened during his administration.
"We can support Najib but there is no need to pull out all of Mahathir's past mistakes on primetime TV," said a Malacca Umno politician.
Mubarak, the organisation of former representative, is one of those groups which has been stuck in a conflicted situation. Its patron is Dr Mahathir and its adviser is Najib.
However, Mubarak president Abdul Aziz Abdul Rahman said the organisation may make a Eid visit to their patron although they know what Dr Mahathir is going to say when they meet.
"Let me put it this way, Najib is not going any time soon," said Abdul Aziz.
Or as a former prime ministerial aide put it: "It is delusional to think that Najib will step down. The main bulk of Umno is with him and for as long that is the case, it is hard to buck him."
Moreover, the 1MDB issue is still unfolding, producing dramatic exposes every other day and lending credence to claims of hidden hands, power play, foreign meddling and a conspiracy to topple the government.
Malaysians have seen how the opposition has pulled out every trick in the bag to inch its way to Putrajaya.
Likewise, Najib and his coalition will do what it takes to hold on to Putrajaya.