Joseph and Mary were betrothed, an agreement that was binding for both of them even though they hadn't yet married ie consummated their union. And there is no mention of a wedding.
Matt 1:20; But when he had considered this, behold, an angel of the Lord appeared to him in a dream, saying, "Joseph, son of David, do not be afraid to take Mary as your wife; for the Child who has been conceived in her is of the Holy Spirit.
Matt 1:24; And Joseph awoke from his sleep and did as the angel of the Lord commanded him, and took Mary as his wife,
Well something happened that was different from when he just betrothed to her.
I believe that couples should refrain from sex until they are married or in the case of homosexuals and lesbians celibacy would be the ideal way.
It seems you are OK with homosexuality... as long as they don't have sex? Or at least no sex until they are married?
1Cor 6:9; Or do you not know that the unrighteous will not inherit the kingdom of God?
Do not be deceived; neither fornicators, nor idolaters, nor adulterers,
nor effeminate, nor homosexuals,
1Cor 6:10; nor thieves, nor the covetous, nor drunkards, nor revilers, nor swindlers, will inherit the kingdom of God.
In the Bible there were many reasons for marriage ceremonies.
First witnesses to the covenant - people to hold these two responsible if one backs out or is unfaithful. No witnesses = no accountability.
Second to track bloodline and ancestry. Not a big deal for some, but it was big for the Jews.
Third for legal accountability - who owns the house if (a) we get divorced or (b) someone dies.
Another part of the legal responsibility is who pays child support for the children or in some cases alimony.
You can still get married by a Justice of the Peace in most towns for about $50.00. He himself and his secretary are all the witnesses you generally need.
But why wouldn't you invite you friends? Unless either of you has doubts, in which case you shouldn't get married.