I went to a similar but different school to the one Charlie went to.
It's not unusual for people to develop a range of accents and adapt to the people they're with. When he's with other old school friends or very wealthy he probably sounds a lot more hoorah Henry. But his family will certainly not speak that same way and so him home/natural accent is bound to be a bit more London. That combined with the people he is with in there will mean his accent ends up where it is.
I do it too. When I went to university I was torn apart for being/speaking posh and developed a flexible accent. I know I vary it now depending on the company I'm with as sometimes I hear 'other' accents coming out of my mouth.
On a different note i quite like Charlie but we've not seen much of him. I always loved Alex but was having a bit of a dip on him but his actions and words last night have redeemed him. I used to like Ellie but we got a first glimpse of how nasty she can turn when Alex didn't just accept her dumping and walk away so I've been waiting to see her true person for a while. She acts like she's sweetness and light but is actually extremely bitchy and catty, and vicious when things don't go her way.
I still like Georgia, she may have done something wrong but it wasn't actually a big deal and she doesn't deserve the level of shit she's getting. Laura acted fantastically with the whole Megan thing and was phenomenally signified and composed I just think that she needs to have a word with herself now and calm down because it is entirely down to her that this whole thing with Georgia has been blown out of proportion.
Also, Jack2 deliberately muddied te waters with it all. He could have just said we had a peck saying hello and a peck saying goodbye. Done. I feel like he was trying to bait Laura into a reaction because he wasn't sure how she feels about him and wanted to see if she'd be jealous.