Perder el culo

[ROBINDESBOIS]

This expression is a bit vulgar but very common.
Exemple:
Cuando sus amigos le proponen algo, pierde el culo y siempre se apunta.
Sin embargo, no importa lo que yo le proponga, que nunca se anima a venir conmigo.

it means that no matter what the other people propose or say, he always sees it fit and leaves everything to go meet them.

In English?

[poli]

In English the term is to drop everything. He'll drop everything if someone if his friends ask him out for a drink

[ROBINDESBOIS]

I like it a lot.

[JPablo]

perder el culo

16 malsonante Ir con mucha prisa a por una cosa, mostrando mucho interés en ella: algunos futbolistas pierden el culo por un contrato millonario.


http://www.oxforddictionaries.com/definition/spanish/culo?q=perder+el+culo&searchDictCode=spanish-english#perder_el_culo


perder el culo por algo/alguien [colloquial], pierde el culo por él she's just crazy or nuts about him [colloquial]
está que pierde el culo por que la inviten she's just dying to be asked

http://www.oxforddictionaries.com/translate/spanish-english/culo

[ROBINDESBOIS]

tiene gracia, y si lo analizas fríamente lo que quiere decir incluso más.

[pjt33]

Curioso, antes sólo he oído «perder el culo» en el contexto de alguien que ha apostado el culo insabiamente.

[ROBINDESBOIS]

hahhahahahhaha, a la cama no te irás sin saber una cosa más.

[Marylander]

It seems to me to imply 'you deviate from what makes you human'...does anyone else see it this way?

[JPablo]

Not really.

Like any idiom, taken literally could give an incorrect impression or be misinterpreted.

From the viewpoint of the native Spanish speaker (as in my case) you only get the idea that "you move your ass fast" (so fast that you almost "lose it"), so as to get something, some objective. (See the Oxford links above).

By the by,
Welcome to the forum! :)

[Marylander]

Ahh, I appreciate that insight.

& thanks very much for the welcome! :)