Praise be to Allah, and may Allah’s peace and blessings be upon the Messenger of Allah, his family and his companions.
As to what follows:
A group of jurists from the Hanafi, Maliki, Shafi and some Hanbali schools of thought are of the opinion that it is desirable to conduct marriage contract in mosques, and what is meant by contract is offer from the woman’s guardian and acceptance from the husband. They based that on the hadith narrated by Tirmidhi (1089) on the authority of Aisha (may Allah be pleased with her) who said that The Prophet (peace be on him) said:
“Publicize this marriage, and hold it in the Masjid, and beat the duff for it.”
Tirmidhi graded this hadith as weak and said: it is strange and Isa Ibn Maymun is a weak narrator in this hadith.
Bukhari said: this is a denounced hadith.
Ibn Hiban said: all his narrations are fabricated.
Therefore many scholars holding the opinion that it is desirable to conclude a marriage contract in the masjid did not infer from this hadith but rather they justified their view by saying that marriage is a form of obedience and worship and it is desirable to it inside the mosques as they are places of worshiping Allah.
What is apparent to me is that marriage contract in the mosque is permissible as enshrined in Hanafi madh-hab. In any case whether we say it is desirable or permissible, it is obligatory to protect the masjid from shouting, amusement and all that which can harm people who are praying because mosques are not built for those purposes but rather they are built for the remembrance of Allah, prayer and recitation of the Quran.
I think the best is to advice on that and assisting each other in protecting the mosque. If a person is not able to help rehabilitate then he should go and pray at another mosque if that does not result to more harm than benefit.
And Allah knows best.