Answer:
Many different relationships can be found in Twelfth Night. Some of those relationships include friendships and false friendships, and there is even an antagonize-victim relationship that gets flipped around.
Maria proves to have somewhat of a friendship with Sir Toby, even though she shows she greatly disapproves of his behavior. We especially see their friendship in their interactions in Act 1, Scene 2 as well as other scenes in which they plan and execute the prank against Malvolio. Even though Maria scolds him, warning that Olivia is very offended by his behavior, their friendly banter shows their friendship. Act 1, Scene 2 also shows Sir Toby's friendship with Sir Andrew, which proves to be a false friendship. We already see it being implied that Toby has only brought Andrew into the house to court Olivia because Toby wants to take advantage of Andrew's money, which we see when Maria asks why he brought such a fool as Sir Andrew into the house and one of Toby's replies is, "Why, he has three thousand ducats a year," showing us just how interested Toby is in Andrew's money (I.iii.20). Later, Toby's false friendliness to Andrew is exposed when Toby declares what he really thinks of Andrew, "Will you help an as.s-head, and a coxcomb, and a knave? a thin-faced knave, a gull?
The antagonize-victim relationship is first shown in Malvolio's antagonism of the other characters, such as insulting Feste's abilities as a court jester and getting on the other characters' nerves for being such a self-righteous "Puritan" (II.iii.129) and telling Sir Toby he should leave the house if he wishes to continue his disorderly drinking. But the other characters turn the tables on this relationship and become the antagonizes while Malvolio becomes their victim through their prank.
One type of relationship found in Twelfth Night is the love triangle. There are actually two different love triangles found in Twelfth Night. Typically, a love triangle usually involves two people who are in love with the same person; however, there can be variations on the theme, just so long as all three people have some sort of relationship amongst each other.
