There is a great deal of evidence which shows that it is obligatory for men to pray in congregation as you will see discussed in detail in the answer to question no. 120. We do not know of any evidence that suggests that a newly married man is allowed not to pray in congregation, apart from a few fuqaha’ who stated that the one who is waiting for his bride to be brought to him is excused from praying in congregation. 

Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) was asked about his opinion on this and he said: We think that the views of the scholars may include those that are wrong and those that are right. What is essential is to refer to the Qur’aan and Sunnah. 

Secondly: 

The scholars who said this were speaking about something that they used to do, whereby it was the man who received the bride, and the bride did not receive the man. The man would be in his house and his wife would be brought to him, and this was an excuse for not praying in congregation, because if he went and prayed in the mosque, he would not be focusing on his prayer because his mind would be distracted, and the Prophet (peace and blessings of Allaah be upon him) said: “There is no prayer when food is ready.” Ibn ‘Umar (may Allaah be pleased with him) would hear the imam reciting whilst he was eating dinner and he would not get up to pray until he had finished eating. If a man is excused for not attending prayer in congregation in this case, then the one who is waiting for his bride to be brought to him is more distracted, so the excuse is obvious. But the custom of people nowadays in our country is different from that; the groom comes to the bride where she is, so it is up to him and he has no excuse for not praying in congregation. End quote. 

From As’ilah al-Liqa’ al-Shahri (29). 

With regard to the wedding being an excuse for not praying in congregation at all, although some of the fuqaha’ have mentioned it, there is no saheeh evidence for that. Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) was asked about someone who did not pray Fajr on the morning of his wedding and his answer was: The groom has to pray Fajr in congregation and not fail to pray in congregation with no legitimate excuse. End quote. 

From As’ilah al-Liqa’ al-Shahri (29). 

Secondly: 

What the questioner is asking about – a newly married man not praying in congregation for a week – is something that some people think is Sunnah. Perhaps they understood this from the words of Anas (may Allaah be pleased with him): It is Sunnah to stay with a virgin for seven (days). Agreed upon – this version was narrated by Muslim (1461). 

But the meaning is not as these people understand it, that he should stay with her for seven days and not go out of the house or pray in congregation in the mosque.  

Rather what it means is that if he marries a virgin and he has another wife, he should allocate seven nights to the virgin, just for her, then after that he should give each wife a night in turn. 

This is narrated from Anas (may Allaah be pleased with him) in the hadeeth quoted above, which was narrated by al-Bukhaari (5214) and Muslim (1461): It is Sunnah, if a man marries a virgin when he already has a wife who was previously-married, to stay with her for seven days, then divide his time (between his wives). And if he marries a previously-married woman when he already has a wife who was a virgin, he should stay with her for three days and then divide his time.  

From this version it is clear that what Anas meant was that he should stay with a virgin for seven days, i.e. give her seven days just for her, then start to divide his time between her and his other wives. 

And Allaah knows best.