Baker's heart has been broken way too many times for him to believe in love. Seth has no plans to disabuse him of that notion. They're both idiots.
All of Baker's adult life has been spent building a respected and successful law firm. The few times he's taken attention away long enough to focus on love, it's always ended the worst way possible. He doesn't believe in happy endings or even good people. That's why he can't understand why he can't shake Seth.
Seth and Baker had some fun once. That's all it was to either of them. Seth believes in science. Chemical attraction. That's all. He's just as baffled as Baker as to why he keeps seeing Baker every time he closes his eyes. That probably means he should stay away.
When they find themselves thrust together again, one of them will have to start believing in more than chemistry. Otherwise, they'll never be healed from the past that shaped them.