Is This Ronnie's Stalker?

Andy has been seen on the square for a few weeks, working on Vincent's basement. From what we know so far, Andy is friends with Vincent's brother Linford, played by Leon Lopez.

He seemed to be a simple background character but things have since changed. He has had more screen time and many more lines than the other builder and even has promo shots, which suggests that there is more in store for this character.

After the builders wormed their way in to giving Jack a quote for the renovations on his house, Jack invited them all out for a drink. So what's the big deal? Andy was nowhere to be seen, Jack asked "Where's Andy?", this might not seem like a big deal but writers put that line in the scene for a reason. The response was that Andy was dog sitting.

The other clue was when Ronnie called on the help of Jack when Hannah had baby Matthew in her arms. The builder boys came running and it was Andy that swooped in and saved Hannah and the baby from an oncoming car.

What are your theories on the stalker,  could it be Fatboy, Charlie or someone completely unexpected?