Digital Spy caught up with series star Johnson to find out how the pair are adapting to having a babe in arms in series two...
What's coming up for Laura and Jamie now that they have a baby together?
"More of the same situations as in the first series - although the bump is now an actual baby, they're still in as much turmoil about their relationship - about how their families get on and how they're meant to be living their lives. But now they're young parents, rather than having a baby on the way...
"So there's similarly frustrating situations for them, I think. They're both a little bit lost, especially Laura. Jamie's still at college doing his A-levels and he's got Mike (Dylan Edwards) and Beth (Yasmin Paige) around, but I think Laura - bless her - is at home with the baby a lot of the time and without much of a peer group.
"Her best friend Danielle (Emer Kenny) is up at uni and she doesn't know any other young mums. There's an episode where she's trying to make her own new social scene with other mums, and that doesn't go too well for various reasons!"
You worked with several real babies on set - what was that like?
"It was great, actually - but it was hard, really hard work. They say never work with children or animals! But it wasn't horrible at all, they were all brilliant babies, all of them very well-behaved.
"And their parents were really nice, 'cos that was the thing I was really concerned about - the parents are in the room, on set, the whole time, and you don't want to get anything wrong when you've got a mum or dad there! We had a couple of sets of twins and I think the mums were just like, 'D'you know what? I'm quite happy to have someone else hold the baby for half an hour!'
"It got hard sometimes. When you're trying to do a complicated scene that takes a few hours and you've got a baby that's grouchy that day because it's just a bit tired, that can be really difficult and stressful for everybody.
Anybody's gut reaction when they hear a baby cry is to do something about it, so when the cameras are rolling, it's really hard because I have to play the scene out. You're fighting all your natural instincts!"
Pramface was picked up for a second series before the first had even aired. That must have given you a massive boost of confidence?
"It was just so exciting. We found out in November 2011 that we'd got the second series, and honestly I was just properly jumping for joy. We had no idea that we'd know [about series two] before the show had gone out - you just never know with these things whether it's going to work out or not.
"We were just so excited and so flattered that people enjoyed it. The response was amazing on Twitter and [from] people just coming up to me in the street and saying how much they loved it. Everyone got really involved in it. We were just chuffed that people liked it, because it was so much fun to make. It's a bit of a gift of a job for me!"
The first series had the same writer and director throughout. Was that the same this year?
"No actually - we had the same writer Chris Reddy, although he had a couple of other writers join him to do additional material, which is quite normal because this is a longer series, so it just needed more hands on deck.
"But we had two new directors this series, because of the way we were shooting it - we had to do it in two different blocks."
Did that change shake things up on-set?
"It's funny because I thought it would and I was quite anxious about it, but then actually because we were filming in the same locations in Edinburgh again... a lot of the crew were the same. It was a lot of the same faces, so it felt like one big happy family - it was really cool."
You've done a lot of dramatic work in the past, but recently with Pramface and also Beaver Falls you've moved into comedy - was that intentional?
"No, it just kind of happened that way. I did a comedy pilot for Warner Bros. - it was from LA but we filmed it in Vancouver. I was playing an American, it was an American production, but that was my first comic role.
"After I did that, I came back from LA and thought, 'I quite enjoyed that comedy stuff - it's quite good fun!' - you never really make a choice to go in a certain direction, because it's up to directors and casting directors what they want to do with you. But I was really pleased when I became a bit more known for comedy, because it's something that I really love doing. I'm filming at the moment on another comedy series."
That's Big Bad World for Comedy Central - what can you reveal about your role in that?
"I actually can't reveal anything about it - it's top-secret! It's only week three of filming, so it's really early days. They don't even know what the transmission date will be yet. But I'm really loving doing it - it's a very different character from anything I've played before.
"I definitely don't want to stop doing drama, but I actually don't think [comedy and drama] are that different - for an actor, it's kind of the same skills that are required, it's just a different format."
Do you think there is scope for a third series of Pramface?
"I think there's definitely scope. I would love to be able to come back to it. At the end of this second series, Jamie and Laura's relationship has changed somewhat from the beginning of the series. I'm not going to say in what way, but it does move on!
"So it would be really lovely if a third series happened for that to be explored a bit more, but it depends on whether the audience loves it and whether the BBC loves it. Fingers crossed!"
Pramface returns to BBC Three tomorrow night (Tuesday, January 8) at 10pm.