Being a stranger at a wedding is not ideal. I know; I once attended a wedding with my wife and she was the only one there I knew. It was even worse for Sampson; he was both a stranger and the groom at the same time.
The groom usually has friends to be their best man and companions. Sampson did not have any men friends in his wedding party, so his father-in-law to-be provided him with 30 companions, but they were all strangers to him. What I’m about to say is not explicit in the Scripture; it is my speculation. I think these men being philistines looked down upon Sampson. I think they made fun of him for not having proper festival or wedding garments. I do not believe they made any attempt to know him but were content to treat him as an inferior stranger. Sampson responded by putting forth a riddle where 30 formal cloaks (not shirts) and fine garments fit for attending a wedding would be the prize.
I believe the father-in-law had given Sampson ruffians as companions. The result was that when they could not solve the riddle, they threatened the bride and the bride’s family. When threatened by the men, Sampson’s new wife made her decision out of ignorance. Sampson was a stranger to her and she did not know his strength and power. Instead of trusting him and seeking his help, she deceived him and betrayed him. It took seven days but Sampson finally told her the secret of the riddle, and she promptly told the ruffians who were playing the part of Sampson’s companions. They wasted no time in claiming the prize.
Sampson recognized that he had been betrayed, and in anger, he traveled 20 miles to a wealthy Philistine city. There the Spirit of the Lord enabled him to kill 30 wealthy men and strip their dead bodies (an unrighteous act). He then returned and paid his debt.
Illustrated truth: When the unrighteous are destroying the wicked, God sometimes helps.