Manga : comes up with them being girlfriends as a "cover" in the next chapter
It's all coming together.
Technically they are 'Ex-girlfriends' for their cover story XD
Benika seems happy and excited though, can't blame her since a juicy romance story/comedy is always amusing lol.
...Though I bet in like 5-8 more chapters they will began to grow to like each other and perhaps even fall in love to become true girlfriends....though the nun-spy seem to have a grudge against the hitmen side/fraction for seemingly possibly killing her family though....
But eh I am sure she will get over it after killing the person/few people that few responsible before eventually finding true love with the enemy spy from Hitmen fraction/side lol :D
7-12 chapters later:
Benika: "I thought you guys were just exes?"
The 2 spies: "...we got back together and work out our issues."