Hi, I'm looking for a descriptive word to be used in the following condition.

If I meet an embarassing occasion, for example, the chair gets broken just when I sit down, I might say "Oh, I need to put off a few pounds".

I'm talking ironically, or sarcastically, or some other better words to express the meaning that I'm talking in a tone of laughing-at-myself because I feel embarassed.

Thank you!
I don't think there is one single word for this situation. The idiom 'laugh at yourself' works well. As for your example, people around you would understand whether you were being serious, embarrassed or 'laughing at yourself' by your tone of voice.
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Am I too late?

This is for anyone else who stumbles across this.

I think the expression that ahava_yin was looking for was "self-deprecation." The story told was an example of "self-deprecating humor."

James Baquet