The Love Hypothesis by Ali Hazelwood

Olive smiled back, gesturing at Adam to order first.
“Coffee.” He darted a glance at her before adding,
sheepishly, “Black.”
She had to duck her head to hide her smile, but when she
glanced at him again, the corner of his mouth was curved
upward. Which, she reluctantly admitted to herself, was not a
bad look for him. She ignored it and ordered the most fatty,
sugary thing on the drink menu, asking for extra whipped
cream. She was wondering if she should try to make up for it
by buying an apple, too, or if she should just lean into it and
top it off with a cookie, when Adam took a credit card out of
his wallet and held it to the cashier.
“Oh, no. No, no, no. No.” Olive put her hand in front of his
and lowered her voice. “You can’t pay for my stuff.”
He blinked. “I can’t?”
“That’s not the kind of fake relationship we’re having.”
He looked surprised. “It isn’t?”
“Nope.” She shook her head. “I would never fake-date a
dude who thinks that he has to pay for my coffee just because
he’s a dude.”
He lifted an eyebrow. “I doubt a language exists in which
the thing you just ordered could be referred to as ‘coffee.’ ”
“Hey—”
“And it’s not about me being a ‘dude’ ”—the word came
out a touch pained—“but about you still being a grad student.
And your yearly income.”
For a moment she hesitated, wondering if she should be
offended. Was Adam being his well-known ass self? Was he
patronizing her? Did he think she was poor? Then she
remembered that she was, in fact, poor, and that he probably
made five times as much as her. She shrugged, adding a