Ser uña y carne

to be inseparable; **to be inseparable**; **to be as thick as thieves**; **to be joined at the hip**; **to be very close**

Ser uña y carne means to be inseparable, to be extremely close or to have a very strong friendship or relationship.

The expression suggests that two people spend a great deal of time together and enjoy a deep bond.

It may refer to friends, siblings, couples or even colleagues.

• are inseparable
• have a very close friendship
• always spend time together
• share a particularly strong relationship
• are almost never seen apart

The image comes directly from the close physical relationship between the fingernail and the flesh beneath it.

Trying to separate them causes pain.

Because of this intimate connection, Spanish adopted the comparison to describe people whose relationship seems equally impossible to separate.

The metaphor has existed for centuries and remains fully alive today.

The expression usually has a positive meaning.

However, it can occasionally be used with irony.

For example:

Esos dos son uña y carne.

may imply that two people always support each other—even when they are clearly wrong.

The tone of voice determines whether the expression sounds affectionate or slightly critical.

Some older speakers still use the longer form:

ser uña y carne, como el dedo y la uña

("to be nail and flesh, like the finger and the nail").

Although the shorter version is now far more common, both expressions are built on exactly the same image: two things so closely connected that separating them would feel unnatural.

Do not translate the expression literally.

English speakers would never say:

They are nail and flesh.

Instead, use expressions such as:

• They're inseparable.
• They're joined at the hip.
• They're as thick as thieves.

The last option is informal and usually refers to close friends rather than romantic couples.