What's the meaning of นมเล็กชอบแก้ไข นมใหญ่ชอบแก้ผ้า It's about small breasts and big ones but what is the exactly meaning.

http://www.thaivisa.com/forum/topic/653056-video-breast-size-oriented-luk-thung-music-video-in-hot-water/

that was quick 555 thanks

Here's one more joke on the same matter:

อกหักแม้นเรื่องเล็ก แต่ เรื่องอกเล็กแม้นเรื่องใหญ่

[òk hàk mɛ́ːn rɯ̂ːəŋ lék tɛ̀ rɯ̂ːəŋ òk lék mɛ́ːn rɯ̂ːəŋ yɑ̀i]

"To be heartbroken is not a big deal; to have a small breast is".

The word play is based on that "heartbroken" is literally "broken bosom"; "เรื่องเล็ก" is literally "a small thing", while "เรื่องอกเล็ก" is literally "a small thing of a bosom" which is understood as "small breast".