Just a fluffy response to a Jasia prompt on tumblr about Guy turning up at Zosia's flat and finding Jac there. Hope you enjoy! :)

Guy Self checked his phone for the third time in the space of 5 minutes. No notifications, no missed calls, not even a text message. He had tried to ring his daughter three times last night and again this morning and still no response. Now he was stood outside her flat contemplating whether or not he was crossing a line. He was sure there was no reason to worry, it wouldn't be the first time she had been busy and ignored his calls, sometimes they wouldn't talk for weeks but he had a strange feeling. He turned his phone in his hand over and over until he finally dropped it into his coat pocket. He had made his way here, he might as well look in, he knocked. At first there was no response.

"Zosia?" He called and knocked again and this time he heard movement inside.

"Dad?" Zosia March opened the door sticking her head out. "What are you doing here?"

"You didn't return any of my calls." He explained looking at her expectantly.

"Oh yes, I'm sorry about that. I was busy…"

"Well, I was in the neighbourhood and thought…"

"You'd check up on me." She concluded, it wasn't necessarily an accusation but she frowned.

"No, not at all, I just…" He shook his head but couldn't convince her.

"Dad."

"Are you not going to ask me in?" He countered surprised that she hadn't yet.

"Well, I'm kind of in the middle of something… but I'll see you at the hospital?" She replied vaguely.

"Come on, I'm here now."

"Zosia, it's fine." A voice sounded from the inside of the flat. He recognised the voice but decided he had to be mistaken. Zosia closed her eyes for a second as if composing herself but then opened the door to invite him in. Guy stepped inside the flat and all the colour drained from his face when he spotted Jac Naylor.

"Jac…" He said slowly trying to make sense of the situation.

"Guy." She replied smirking ever so slightly. She took a sip of her coffee.

"What are you…" He began to ask as his brain was still trying to piece the impossible together. He recognised the t-shirt Jac was wearing as one of his daughter's old university shirts and his heart sank. "You're not…" He looked at his daughter who seemed to be at a loss for words. "Please tell me you're not…" He looked back at Jac panicked and the CT consultant smirked as she got to her feet.

"Don't think too hard Guy, your brain might explode." She chuckled and walked past him to Zosia's bedroom. Guy was speechless. Jac was wearing nothing but that shirt and underwear. "Eyes up Guy." She said knowing full well he would be looking at her legs.

"Nothing I haven't seen before…" He started to say but realised the circumstances when Zosia interrupted him.

"You think it's ok to look at my girlfriend like that?" She asked crossing her arms in front of her chest. He meant to protest, remind her of their shared history but was too caught up on her phrasing.

"Girlfriend? Are you serious?"

"Ahm… well…" She only realised what she had said, she hadn't even had this conversation with Jac yet, so she was completely unprepared to talk to him about it.

"Are you serious, Zosia?" He asked again more forcefully.

"Do you have a problem with that?" She retorted clenching her jaw, his apprehensiveness strangely made her more confident.

"Well, yes, actually!" He replied looking around to check Jac hadn't returned. "What on Earth are you thinking?!"

"This is non of your business." She shot back angrily. "See this is why I haven't told you!"

"Do you have any idea how inappropriate this is? She's your mentor, she's closer to my age than yours…"

"Oh really, I had no idea." She replied dryly.

"Zosia, you will put an end to this or…" He took a step towards her and she moved back ever so slightly. She couldn't remember the last time she had seen him so angry. She hadn't exactly expected him to be thrilled but his reaction was completely disproportionate.

"No I won't." She retorted trying to sound firm but it was obvious that she was insecure.

"I'm not asking!" Guy growled taking another step forward and Zosia bumped into the kitchen island finding herself trapped. She wasn't used to feeling like this, she was more than capable of fighting her own battles but it was different with her father. He had a temper and a way of making her feel like a child again.

"I think that's quite enough Guy!" Jac's sharp voice cut through the tension like a knife. She had gotten dressed in a white shirt, dress trousers and heels looking much more intimidating than she had five minutes ago. It was the look of fierce determination on her face though, that took Zosia's breath away.

"You seriously need to get out Jac, before I forget myself!" He exclaimed, her interruption was only infuriating him further.

"No, YOU need to seriously get out." She retorted every bit as angry as he was as she walked up to confront him.

"Jac, I swear, if you don't…"

"What are you going to do? Strike me? Do it, go on. Do it and see what happens." Decisively she stepped between him and Zosia forcing him to move back.

"This is completely unacceptable." He insisted. "I won't let you…"

"Won't let me do what? In case you haven't noticed, your daughter is more than capable of making her own decisions, you have absolutely no business being here, neither one of us has asked you here so why don't you do us a favour and leave."

"You will regret this, Jac…" He threatened but she wasn't intimidated.

"Just try something Guy, please, try something and give me a reason to have your job. Nothing would make me happier than kicking you off my ward for good. I swear if you do anything to hurt Zosia you will regret it and that is not an empty threat."

"Jac, it's okay…" Zosia tried to calm her down half-heartedly, she didn't want the situation to escalate any further but she couldn't deny how much Jac standing up for her meant to her. She grabbed on to her hand standing behind her. She felt safer than she had ever felt before. The consultant squeezed her hand lightly but didn't break eye contact with Guy, she was determined to see him off. Zosia move closer behind her, she paced her other hand on Jac's hip and stood against her. "It's fine, he'll be fine."

"This isn't over." Guy growled infuriated by the open display of affection between them.

"I think it's time you left, Dad." Zosia said firmly.

"You heard her, get out." Jac added more harshly before he could protest. He was desperately searching for a comeback but there was nothing he could say or do.

"We'll see what Hanssen has to say about this." He finally managed to piece together.

"Oh so you're not above harming your daughter's career then?" Jac asked mocking him.

"Rather than allowing this to continue." He spat and stormed off.

"Jac, what if he really…" Zosia sounded worried once the door had slammed shut behind him, she wouldn't put it past her father to stab her in the back like that just so he could have his way. If he played it right, he would be getting them into a lot of trouble.

"Well, it's a good job then that I've been on the phone to Hanssen earlier explaining everything isn't it?" Jac half-smiled and turned around to face her girlfriend. She brushed her hair behind her ears and Zosia looped her arms around her hips leaning against the kitchen island.

"Thank you." She breathed looking up at her in adoration. "No-one's ever… you know…"

"No-one talks to my girl like that." Jac said taking her face in her hands.

"Your girl?" Zosia chuckled and Jac smirked.

"If that's what you want?"

"Nothing would make me happier." She leaned forward and kissed her softly.

"Hmm good, because it would have been really embarrassing if I had to tell Hanssen I was mistaken…" She grinned and kissed her more deeply.