I think it's better to play safe and not attempt to qualify it.

@@ -19 +18,0 @@
-<s_inf>light-heartedly, flirtatiously</s_inf>

It might be safest to just remove it. That, or basing the 
note more closely on the jitsuyo definition and make it a 
"sometimes" to cover our bases. 
"sometimes used playfully"?

i ran this past a friend who is half-japanese and was raised bilingual and i asked him that if a woman said いやあん in a sexual context would it be considered "light-hearted/flirtatious", and after a bit of back and forth, his final comment was "i'm not kidding, there is a rape element to iyan."  he's not the type to throw that around lightly

so perhaps the current note is not adequate

Maybe this?

@@ -18,0 +19 @@
+<s_inf>light-heartedly, flirtatiously</s_inf>
@@ -21 +22 @@
-<gloss>don't (very light-hearted)</gloss>
+<gloss>don't</gloss>