There was so much that didn't work between them - Bobbi talked about work all the time. Her job was her life, and she had to discuss it ad nasueuem or she felt like she'd explode. Clint wouldn't and that drove her nuts. Or the times she'd be able to talk about other things, and then realize she'd spent the last ten minutes talking to a Clint who had mentally checked out. That was just the tip of the iceburg when it came to the dysfunction.
But she worried about him when he was gone. He took a knife for her hours after meeting her (and mere minutes after she had threatened to shoot him in the kneecaps if he didn't get out of the godamn way) and she had missed him. Although she knew that this window of getting along was already closing and in a few hours she'd be looking at SHIELD reports and wondering when he'd get sent out again.
But she'd worry about the getting along window closing later.
"Well I better double check, you know SHIELD likes to be very thorough. And I am a scientists." Who now spent more time on the firing range, then she did in the lab, "and you know how we like to double and sometimes even triple check things ..."
The next thing out of her mouth she blamed on the hour. She got brutally honest once it hit 2:00 AM it seemed, even honest with herself.