Por la noche me quito el rímel con desmaquillante y luego me pongo la bata.

In Spain, por la noche is the normal way to say at night / in the evening at night-time.

• Por la noche = at night
• por la mañana = in the morning
• por la tarde = in the afternoon / evening

En la noche exists, but it is much less common in this general time-of-day sense, especially in Spain. It is more likely in specific contexts, depending on region or style.

So for a routine sentence like this, por la noche is the natural choice.

Because in Spanish these verbs are often used reflexively when the action affects your own body or what you are wearing.

• quitar = to remove / take away
• quitarse = to take off / remove from oneself
• poner = to put / place
• ponerse = to put on oneself

So:

• me quito el rímel = I take off/remove my mascara
• me pongo la bata = I put on my robe

The me shows that I am doing it to myself / for myself.

The difference is whether something is removed in general, or removed from oneself.

• Quito el libro de la mesa = I remove the book from the table
• Me quito el abrigo = I take off my coat
• Me quito el rímel = I remove my mascara

So in this sentence, quitarse is used because the speaker is removing makeup from their own face.

Spanish often uses the definite article (el, la, los, las) instead of a possessive like my, especially with:

• body parts
• clothing
• personal items closely connected to the person
• things obviously belonging to the subject in context

So Spanish prefers:

• me lavo las manos = I wash my hands
• me pongo la chaqueta = I put on my jacket
• me quito el rímel = I remove my mascara

Even though English usually says my, Spanish often says the when ownership is already clear from the reflexive pronoun.

For the same reason: Spanish commonly uses the article instead of the possessive when it is obvious whose item it is.

• me pongo la bata literally looks like I put on the robe
• but it naturally means I put on my robe

Because of me pongo, it is already clear that the robe is the speaker’s.

In this sentence, la bata most naturally means a robe or dressing gown worn at home.

But bata can mean different things depending on context:

• dressing gown / robe at home
• lab coat
• smock / gown

Here, because the sentence is about a night routine, robe/dressing gown is the best interpretation.

Desmaquillante means makeup remover.

In Spanish, when talking about the material, product, or means used to do something, it is common to say:

• con agua = with water
• con jabón = with soap
• con desmaquillante = with makeup remover

No article is necessary. It sounds like using the product in a general sense.

You could also hear:

• con un desmaquillante suave = with a gentle makeup remover
• con el desmaquillante que compré = with the makeup remover I bought

So the version without an article is completely natural.

Yes. Both are understood, but they are a bit different in feel.

• rímel is very common in Spain in everyday speech
• máscara de pestañas is also correct and a bit more descriptive or formal

So:

• me quito el rímel
• me quito la máscara de pestañas

Both work. In casual Spain Spanish, rímel is very natural.

Because in Spanish it is treated as a fully adapted Spanish word and follows Spanish stress rules.

The written form rímel shows that the stress is on the first syllable: RÍ-mel.

Without the accent, Spanish spelling rules would suggest a different pronunciation. So the accent mark tells you where the stress goes.

Yes, but it depends on the verb form.

With a conjugated verb, the reflexive pronoun normally goes before the verb:

• me quito
• me pongo

With an infinitive or gerund, it can attach to the end:

• quiero quitarme el rímel
• voy a ponerme la bata
• estoy quitándome el rímel

So in this sentence, because quito and pongo are fully conjugated present-tense forms, me goes before the verb.

Because in Spanish, just like in English, the present tense can describe:

• what you are doing now
• what you usually do
• a habitual routine

So Por la noche me quito el rímel... can mean:

• At night I remove my mascara...
• Every night I remove my mascara...
• At night I usually remove my mascara...

The context decides whether it is a habit or a current action. Here it sounds very much like a routine.

Yes. Por las noches emphasizes a repeated habit more clearly.

Compare:

• Por la noche = at night / in the evening
  This can describe a general time or a routine.
• Por las noches = at night(s) / every night / at night in general
  This sounds more clearly habitual.

So both are possible, but:

• Por la noche me quito el rímel... = natural
• Por las noches me quito el rímel... = also natural, and more clearly as a habit

Luego means then / afterwards, and y simply links the two actions.

• me quito el rímel con desmaquillante y luego me pongo la bata

This is very natural and means:

1. first I remove my mascara
2. then I put on my robe

You could also say:

• ...con desmaquillante; luego me pongo la bata
• ...con desmaquillante y después me pongo la bata

But y luego is a very normal, everyday way to connect the sequence.

Yes. In Spanish, quitarse is not limited to clothing. It can also be used for things you remove from yourself, including makeup.

Examples:

• quitarse el abrigo = take off your coat
• quitarse las gafas = take off your glasses
• quitarse el maquillaje = remove your makeup
• quitarse el rímel = remove your mascara

So this use is completely natural.