Texting Shorthand: What do the letters stand for?

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Across
  1. 2. IMO means? (3 words)
  2. 5. JK means? (2 words)
  3. 7. TTYL means? (4 words)
  4. 8. OMW means? (3 words)
  5. 9. NVM means? (1 word)
  6. 10. IKR means? (3 words)
  7. 11. OFC means? (2 words)
  8. 12. ROFL means? (4 words)
  9. 13. CYA means? (2 words)
Down
  1. 1. SMH means? (3 words)
  2. 3. LMK means? (3 words)
  3. 4. BTW means? (3 words)
  4. 6. YOLO means? (4 words)
  5. 10. ILY means? (3 words)