No one quite understood the relationship between Dexter and Mandark. It was clear they weren't lovers, but it was also clear that they weren't enemies. Though they bickered, quarreled, and fought, they never seemed truly intent on bloodshed as they had before the war began. Mandark would shoot a remark, Dexter would insult just as quickly, and then it was impromptu.
Sometimes there would still be tension, sometimes just a pause, and sometimes they would resume whatever they were doing beforehand. Mandark still tried to tease Dexter, but both seemed to think of it like a challenge now. Whenever Mandark succeeded in irritating Dexter, the two would shrug and walk away, Mandark sometimes smiling.
The boys lost their interest in this after a while, and eventually, the two became good friends.
When Dexter would design a weapon, Mandark would help. Dexlabs and Mandark Industries merged and became better than ever. Just to mess with everyone, they would tease those around them, Dee Dee included.
Once Dee Dee walked in on them (Dexter just so happened to be leaning over the table a bit, ahem, suggestively, towards Mandark) and squealed, blushing like mad, before dashing out as fast as her long, gangly limbs would take her. Then she heard cackling from inside the lab, Dexter's particularly strong, and a good cheer to Dexter before quiet settled over them. "I swear those two!"
Dee Dee's threatening tone drifted off. It was then she realized that Dexter and Mandark were becoming best friends. This would be Dexter's second. Now, Dee Dee was dating Ben, and she cared about him, but at that moment, she felt pure affection and adoration towards the "evil genius" that had managed to get through the tough exterior her brother put up to protect him. She smiled at the closed door and hurried off.
The two had work to do, and, for once in her life, she thought it was important that she didn't interrupt her little brother while he was working.