Sparknotes says in regards to the following quote "VALVERT: Your nose is . . . very big. CYRANO: Yes, very. VALVERT: Ha! CYRANO: Is that all?" that "Remembering the promise he made to Roxane to keep Christian safe, Cyrano responds to Valvert’s ridiculing of his nose with biting, ironic criticism instead of violence." At this point in time, Roxane has said nothing to Cyrano about Christian, and indeed, Cyrano kills Valvert upon the final line of his balade.