joined at the hip 

Always together, like siamese twins, inseparable, where one goes the other is sure to follow.

Amy and her boss were joined at the hip; you never saw one without the other.

joined at the hip by RadioRay September 24, 2005

joined at the hip 

absolutely inseparable, (implying as inseparable as conjoined twins attached at the hip)

The pastor was joined at the hip with his church. He just wouldn't leave.

joined at the hip by The Return of Light Joker January 9, 2011

joined at the hip 

Another way of saying two people are presently engaging in sexual intercourse.

Mommy, what's that noise upstairs? Oh little Timmy! Your brother and sister are going at it right now. You might say they are joined at the hip!

joined at the hip by Adolfo Hitlaro October 11, 2020

joined at the hip-hop 

Inseparable friends due to mutual affinity for hip-hop.

Son to ma: "Bobby gave me this gold record with samples from De La Soul and we just poured over his hip-hop vinyls like all day."
Ma to son: "Sounds like you and this Bobby are joined at the hip-hop."

joined at the hip-hop by @Bugyack October 21, 2013