All you've done is simply walk into the room and he feels himself tense. Your steps aren't even imposing. Barely above a scamper and yet he has become acutely aware of how he's braced as though expecting a fight.
It takes a conscious effort to get his body to relax, especially after you get closer, setting up your small work station in the lab on the other side of the table across from his.
He knows you can't help it, but when he looks at you, he sees your father. The cruel, snide smile that borders on a sneer has never once graced your lips. And yet it's all that he can imagine whenever he sees you in mirth. You've done nothing to help the man and yet Barry can't stop envisioning you standing next to the him, his right-hand in whatever malicious scheme he plans on pulling next.
It's unfair of Barry, and he knows it. You were just as surprised when Eobard Thawne had revealed his ploy. Attacked and then disappeared in a flash of lighting that seemed to practically snarl as they evaporated with a hum of static, leaving you and the others confused and hurt.
He knows it's unfair to judge you by your father. You didn't choose the man. Didn't choose a man who would abandon you in search of power. In search of vengeance. Conquest. That wasn't who Barry had thought he chose to work. You'd both been duped. Victims of manipulation and exploitation. And yet-
He catches himself staring at your down-turned face as you work, and grimaces internally. If he keeps trying to keep you at arms length like he has been, then he'll probably end up making his own fears come true in a self serving prophecy as he drives you to your father's opened arms.
He can't keep treating you like you're a threat, or some underlying villain ready to drive a knife into his back when he lets his guard down. So he sets down his own equipment and clears his throat till you're looking at him with those all-too familiar eyes. "Want to take a break and pick up a coffee or something?"