Не обижайся на меня, пожалуйста.

Обижайся is the imperative form of обижаться.

In this sentence, it is:

• imperative = used to tell someone not to do something
• singular informal = said to one person you address with ты
• reflexive = it ends in -ся

So не обижайся is the informal singular command don’t be offended / don’t take offense.

If you were speaking politely or to more than one person, you would say:

• Не обижайтесь на меня, пожалуйста.

The -ся is the reflexive particle, and it is part of the verb обижаться.

A learner may expect reflexive verbs to mean something like do something to yourself, but in Russian that is not always how they work. Very often, a verb with -ся simply has its own established meaning.

Here:

• обидеть = to offend someone
• обидеться / обижаться = to become offended / to take offense

So обижаться is the normal verb for being offended or taking offense.

This is a very common question because Russian often contrasts imperfective and perfective verbs.

Here the verb pair is roughly:

• обижаться = imperfective
• обидеться = perfective

In negative imperatives, Russian very often prefers the imperfective:

• Не обижайся = don’t be offended / don’t take offense

This sounds natural and standard.

You may also hear:

• Не обидься

That is possible too, but it feels a bit more like:

• don’t get offended
• please don’t take this the wrong way
• often said before or after saying something potentially unpleasant

So:

• Не обижайся = the more neutral, common negative request
• Не обидься = also possible, but a bit more focused on one specific moment of becoming offended

Because обижаться normally goes with на + accusative when you say who someone is offended with / at.

So the pattern is:

• обижаться на кого? на что?

Examples:

• обижаться на брата = to be offended at one’s brother
• обижаться на друзей = to be offended at one’s friends
• обижаться на меня = to be offended at me

So на меня is required by the verb.

Because after на with this verb, Russian uses the accusative case.

The pronoun я changes like this:

• nominative: я
• accusative: меня
• dative: мне

Since the construction is обижаться на кого?, you need the accusative:

• на меня

not

• на мне
• мне

Often yes, but not always perfectly.

Обижаться can cover:

• to be offended
• to take offense
• to feel hurt
• sometimes even to sulk or feel slighted, depending on context

So the emotional range can be a little broader than English be offended.

In this sentence, it usually means something like:

• Please don’t be offended with me
• Please don’t take offense at me
• Please don’t be upset with me

The exact English wording depends on context.

Not quite.

• обижаться на меня = be offended at me / with me
• обижаться из-за меня = be offended because of me

Sometimes the ideas overlap, but they are not identical.

На меня points to the person the emotion is directed toward.
Из-за меня points to the cause.

In your sentence, на меня is the normal choice.

Пожалуйста makes the request softer and more polite.

Without it:

• Не обижайся на меня.
  This is still fine, but more direct.

With it:

• Не обижайся на меня, пожалуйста.
  This sounds gentler, more like a sincere plea.

Russian often uses пожалуйста with requests, just like English uses please.

It is quite flexible.

All of these are possible:

• Не обижайся на меня, пожалуйста.
• Пожалуйста, не обижайся на меня.
• Не обижайся, пожалуйста, на меня.

The most natural version for many situations is the one you were given:

• Не обижайся на меня, пожалуйста.

Putting пожалуйста first can sound a little more emotionally emphatic:

• Пожалуйста, не обижайся на меня.

It is informal singular.

You use обижайся when speaking to:

• one friend
• one family member
• one child
• someone you address with ты

For formal or plural you, use:

• Не обижайтесь на меня, пожалуйста.

So the difference is:

• не обижайся = informal singular
• не обижайтесь = formal singular or plural

The stress is:

• обижАйся
• менЯ
• пожАлуйста

A rough pronunciation guide:

• Не обижайся на меня, пожалуйста.
• nye a-bee-ZHAI-sya na mi-NYA, pa-ZHA-luys-ta

A few useful notes:

• unstressed о is reduced and sounds closer to a
• не is usually pronounced close to nye
• -ся here sounds like sya

It is usually a gentle request, especially with пожалуйста.

The tone depends a lot on context and intonation:

• soft voice: sincere, apologetic, warm
• sharp voice: can sound defensive or impatient

Most often, this sentence sounds like:

• Please don’t be upset with me
• Please don’t take offense

So grammatically it is an imperative, but pragmatically it is often more of a plea than an order.

Yes, and that is a very useful comparison.

• Не обижайся на меня = don’t be offended / don’t take it personally / don’t feel hurt
• Не сердись на меня = don’t be angry with me

So:

• обижаться is more about hurt feelings or taking offense
• сердиться is more about anger

In some contexts they can both fit, but they are not exact synonyms.

Because Russian usually does not need to state the subject pronoun when the verb form already shows it.

In English you say:

• Don’t be offended with me

In Russian, the verb form обижайся already tells you this is a command to you (informal singular), so ты is normally omitted.

You could add ты for emphasis, but it would usually sound unnecessary:

• Ты не обижайся на меня.

That can be used in conversation, but the basic sentence sounds more natural without the pronoun.