Romans 1:26 For this cause God gave them up unto vile affections: for even their women did change the natural use into that which is against nature: 27 And likewise also the men, leaving the natural use of the woman, burned in their lust one toward another; men with men working that which is unseemly, and receiving in themselves that recompence of their error which was meet.
Especially if the person in question who is doing the marriage vows, asks if there are any objections to the consummation of the marriage. The parents in such instances would naturally recoil from raising their hands in a public objection, for doing so would almost certainly cast a dark shadow over the entire ceremony. This in turn could potentially trigger a very bitter backlash from the persons at the altar, and it could create deep wounds that might never heal with the passage of time.
In addition, if the parents in their heart of hearts are decidedly against any such union, yet may choose to attend, just to show support for their kids, they will open the door for severe temptation to compromise their conscientious objections. They would be invited to take pictures with those who are getting married, the parents would have to walk up the aisle to give the engaged persons away, and throughout the entire festivity, their hearts will be bleeding internally, as they witness that which they know is contrary to God’s will, and favor.
These are just a few of the potential results if God-fearing parents decided to attend. In the spiritual realm, we are counseled against placing ourselves knowingly in the way of temptation, for we would almost certainly be taken advantage of by invisible foes.
2nd Corinthians 6:16 And what agreement hath the temple of God with idols? for you are the temple of the living God; as God hath said, I will dwell in them, and walk in them; and I will be their God, and they shall be my people. 17 Wherefore come out from among them, and be you separate, saith the Lord, and touch not the unclean thing; and I will receive you. 18 And will be a Father unto you, and you shall be my sons and daughters, saith the Lord Almighty.
May The Lord add His blessing to the study of His word. God bless!