Maria runs a blog in which she works out the statistics of various apocalyptic scenarios under her initials, MCL, and Jay has been commenting on it under the handle Actual Physicist. Under their online personas, they flirt with math. I'm not normally a huge fan of enemies-to-lovers scenarios. (Which is not at all to be confused with obsessive love/hate relationships, of the kind more likely to be seen in Sherlock/Moriarty fanfic than in Romance novels. Those aren't supposed to have happy endings and therefore are an entirely different thing.) But in this case, I was convinced that both of them, but especially Jay because it's more his fault, realize how they've messed up and that they're going to need to do better in the future. But most important is the dialogue. This is Courtney Milan, and so, as always, the dialogue is pure gold. There is, as I mentioned, flirting with math. And we meet Anj, Maria's former roommate and a lead in a future book, who has a genetically engineered glowing shark named Lisa, which is a good enough reason to read a book right there in my opinion. There's even a cameo by Adam Fucking Reynolds, which you will probably appreciate more if you have read Hold Me, but there aren't really any spoilers for it, so feel free to read this first and the story of how Maria's current roommates got together later if you're so inclined.
For those making it a point to diversify their reading: Maria is trans and Jay is bi. For Jay, that basically just means that one of the two significant exes he mentions is a guy. For Maria, things happened in her backstory due to her being trans that affect her relationships in general, but in her relationship with Jay in particular it's a non-issue. There's also not a couple in the cover art of any book in this series that doesn't appear to be interracial.
I'm looking forward to every book in this series... but maybe mostly the one with the code name "Sharks."