As long as it is a normal marriage, it is not fornication, it is normal.
So, what is a "normal marriage"?
According to China's folk customs, there are many different standards:
Some people think that getting a marriage certificate is a normal marriage.
Some people think that the wedding reception is held in a hotel, even if it is a normal marriage.
Some people think that with parents' orders and matchmakers' words, you can get married normally.
The principle of Buddhism is: obey all beings.
What are the customs of local sentient beings? We will recognize the local standards.
According to the third criterion, you belong to a normal marriage, not debauchery.
According to Christianity, a wedding in a church can only be considered as marriage if it is witnessed by a priest and approved by God.
Buddhism never needs to hold a wedding in a temple, witnessed by a monk and approved by the Buddha.
The principle of Buddhism is: obey all beings.
Buddhism opposes lewdness, not righteousness.
There is nothing in the Buddhist scriptures: people who don't get a marriage certificate are immoral.
There is no mention in the Buddhist scriptures that a group of people who drink and eat meat in a hotel get married.