Related for Gittin 118:19

What is the order [in which the servants] pour the cup [of wine to the people eating]? In the middle of the meal, they (i.e. the servants) begin [pouring the wine] with the [most] senior [person]. After the meal, they (i.e. the servants) begin [pouring the wine] with the [person] who will lead [everyone] in the Birkat Hamazon (Grace After Meals). If [the person who was going to lead everyone in Birkat Hamazon] wanted to give honor to his Rebbi (teacher) or to someone who is greater than him [and have the servants pour his cup of wine first], he is allowed to do so.

Two [people who are eating together] have to wait for each other [to continue eating from their] dish (i.e. one of them cannot eat from the dish while the other one has paused from eating for some reason). [However] three [people who are eating together] do not have to wait [for one person who paused to continue eating from his dish]. [The person] who says the Beracha (blessing) [in the beginning of the meal over the bread for everyone], gets to take [the bread into his hand] first. If he (i.e the person who said the Beracha over the bread for everyone) wants to give the honor [of taking the first piece of bread into the hand] to his Rebbi (teacher) or to someone who is more senior than him, he is allowed to do so.