He'd first witnessed it just after the Townhouse, a "side bar", though he didn't know they called them that then. He'd escorted Olivia and Noah home- needing to know she was OK. After Noah was in bed- he'd offered to order dinner while she showered. But when he'd walked back to the bathroom to ask what she wanted- he could hear her on the other side of the door. Crying. It took him a minute to realize she was talking to someone.
"Barba, I couldn't stop him- I was right there" she sobbed. His heart broke for her. He decided to give her space- order for her. When she emerged from the shower, over 30 minutes later, she put on a brave face. He let it happen as they ate dinner- content in each others company. They'd only been dating, if you could call it that, for a couple weeks. Barba had been her partner for years now. He'd need to earn her trust- especially considering their past. The chance to do so should be enough for now.
She finally gave it a name during the case involving Commissioner Abraham. They were supposed to grab drinks- but she'd said she'd gotten caught up- she and Barba needed a "side bar". Then it turned out Abraham had attempted suicide.
After the fallout over her temporary transfer the side bars had subsided. He and Olivia had drawn closer while Barba seemed to fade into her regular work life. He'd never felt threatened by Barba but he had to admit- his relationship with Olivia seemed easier with the ADA in the background.
When Dodds died he could see Olivia slipping away- he needed to do something. The Paris trip seemed a perfect distraction. And aside from her checking in with Barba's detail every other day- it worked. She seemed really happy. He was more than happy to be a part of that.
But on their return- Old Olivia came back and with her the side bars. While she seemed content and settled in their new life together- on the hard days- she often called saying she'd be late, that she and Barba needed to "side bar" about the latest case.
He wrote it off as colleagues who'd gone through the fire together. After all- Barba was the only person she could really talk to about what was going on at work. It made sense.
Tonight though- he finds himself in her office- watching one of their "side bars" through the two-way glass. She and Barba stand in the interrogation room- packing up their folders- when she finally turns to him to say something.
Tucker can't help himself-he reaches for the switch on the wall- hoping to catch their conversation. He misses the first couple of words but catches Olivia admitting, "Tucker asked me to marry him."
The shock on Barba's face would be apparent to anyone- but the ADA does his best to hide it "Wow- that's- I"
"I haven't said yes yet" she rushes out.