Multifaceted concept.
  1. Directive
    Instructions given (with varying degree of intensity) to a lover in hope (or expectation) of another good hard romping.
  2. Query
    Request made to a lover when hoping for a second boom.
  3. Curse
    Comment made after being screwed (in the bad way), sarcastically suggesting that since offending party has had their way with you, a repeat performance wouldn't make much difference.
  4. Exclamation
    Remark of surprise used by advanced vulgarians in place of "Darn!", "Gosh!" and "Shucks!"
  5. Sign/Countersign
    Broken into two segments "roll me over" and "fuck me again", and spoken by two different people in sequence, this phrase can be used to convey a shared sense of amazement, disbelief, shock, or anger.