Sid is Beth's personal guard, and watches over her gun store. He is quite notable for being a very humorous person, which is a rare characteristic in the Fallout world. Although no romantic connection is known between Sid and Beth, Gunther remarks that Beth is "sweet on her bodyguard Sid." At one point of being spoken with, Sid will scream "She's mine, Don't even think of it!"
When the Vault Dweller tries to speak to him, he will comically make a jab at him or Beth herself. Beth replies angrily with threats she clearly never follows through on. He will also make comical remarks depending on the Dweller's current attire.