I think it was more likely that, since a wedding feast could easily last a week, Jacob was probably too drunk to know who he was with.
1) There is no suggestion of Jacob or anyone else drinking.
2) Getting drunk was shameful in ancient Israel and condemned by the Law and the prophets. There is no suggestion that Jacob ever gave himself over to this sin at any time and therefore it would be sinful for us to accuse him without evidence.
3) If thinking that people were allowed to get smashed at weddings with no such evidence of this mindset from either the scriptures or ancient Jewish literature, one were to go beyond evidence and accuse Jacob of being so drunk he could not know who he is sleeping with, then one has to explain how that works. Having once had a daily hard pounding alchohol habit whereby I drank myself to sleep daily and consumed upwards of 30 or more beers a day, I was never able to arrive to a state whereby I could would be able to perform these marrital duties while at the same time not know who it was, UNLESS it was in pitch dark.
Drunkeness to the point of no consciousness (passed out) does not allow for the rest to function.
4) If you follow the text it is specific about times. Mentions being there a month. Then mentions that evening. There is no space allowed for a week of festivities. "... and gave a feast.
23But when evening came..."
After Jacob had stayed with him for a whole month, 15Laban said to him, “Just because you are a relative of mine, should you work for me for nothing? Tell me what your wages should be.”
16Now Laban had two daughters; the name of the older was Leah, and the name of the younger was Rachel.
17Leah had weak
a eyes, but Rachel had a lovely figure and was beautiful.
18Jacob was in love with Rachel and said, “I’ll work for you seven years in return for your younger daughter Rachel.”
19Laban said, “It’s better that I give her to you than to some other man. Stay here with me.”
20So Jacob served seven years to get Rachel, but they seemed like only a few days to him because of his love for her.
21Then Jacob said to Laban, “Give me my wife. My time is completed, and I want to make love to her.”
22So Laban brought together all the people of
the place and gave a feast. 23But when evening came, he took his daughter Leah and brought her to Jacob, and Jacob made love to her.
24And Laban gave his servant Zilpah to his daughter as her attendant.
25When morning came, there was Leah! So Jacob said to Laban, “What is this you have done to me? I served you for Rachel, didn’t I? Why have you deceived me?”
I don't know exactly, I am ruling out drunk as it does not make sense how that would even work, (having lots of drunk experience I can't see that being a reason that fits) I am going with it being too dark to see. That I can imagine exactly how that could work. Therefore it seems like it was a normal way they did it. Probably religious reasons. Probably thought these things should not be seen.