Hmm...  So, my question regards the "Earth-247" version specifically.
https://comicvine.gamespot.com/duplicate-girl/4005-1262/

The question is: "So what happens when Luornu has split into three (different) people and one of them meets the perfect guy who (in reality) is 'The Perfect Guy For Her'?"

1) No more interest in "merging" with the other two.  At all.

...but wait!  What happens if she *does*?  Do the other two automatically receive all intimate knowledge of Mr. Perfect?  Do they get JEALOUS?  (Heaven forbid!)  Do they impersonate their twin (because, you know, "intimate knowledge") and sample the wares?

...but we all know that Luornu #x is smart enough to avoid that silliness!  And even WARN her partner of her (two) twin sisters who know nearly everything about her!  She'll probably demand that code words be used with all encounters to ensure authenticity!  Lol!

Sadly, most guys would probably ignore these silly demands and fall into "the same ol' trap" of her twins.  ie: deal-breaker and heart-breaker.

Note: all of this would apply to each twin (consider the "Luornu #x" reference, above.)

Edit: Also note that merging would NOT be necessary for a little "treacherous impersonation" to take place! 

Edit, Edit, and MORE trouble!  Sooner or later, the Call for the Greater Good will require her to merge with her twins.