What the heck. May as well include it.

17 tweets these past 24 hrs

I disagree, I think it being common, and being obviously more common than similar possible constructs, is why we include any compound noun 
in the dictionary. I don't think it's weird to expect an unabridged dictionary that doesn't censor itself to have an entry like this. I 
don't think it's unthinkable it could be usable for reverse lookups (remember that reverse lookups aren't always exact but happen through 
google which is good at throwing up relevant weblio's ei-wa pages which include our definitions)

http://www.edrdg.org/wiki/index.php/Editorial_policy#Is_it_worth_including.3F
"is it not what someone reasonably proficient in Japanese would come up with when trying to express the English meaning in Japanese?"

I don't think that fact alone justifies its inclusion. "Clothed sex" is probably the most common term for this in English but I wouldn't expect to find it in an EJ dictionary. It's not as though this would be helpful for reverse lookups.

着衣セックス 15 tweets past 24 hrs
着衣エッチ 4 
着衣ファック 7 past week

I think this is worth having. There's a million ways to phrase this,
服を着たエッチ
服を着たままの性行為
服を着たままセックス
etc. etc.
but this seems to be the most common by far on Twitter.
Should probably have a col tag (I doubt this is how a Jp art historian would describe a 春画 featuring this for 
example)

@@ -11,0 +12 @@
+<misc>&col;</misc>

It gets a lot of hits online but I don't think it needs to be an entry.