Angels

I have 2 Angels n was of the impression 1 was male n 1 female though I now think they could both be male as there is alot of flexing n chest bumping going on. They don't seem to be inflicting harm but I would hate to lose 1 of them. Can anyone sex from a picture? The silver one seems to be developing the male hump on its head

Hi, I have had a look at your photo's and the koi is definitely male - he's definitely growing a hump and there's also signs of an enlarged chest developing too. A male angel that develops are large nuchal hump usually develops a large chest too. My own male angel is testement to that
 

 
As for the silver angel, I'm struggling to tell whether that one is male or female. It has a more rounded head and pointed upturned nose which can look like a nuchal hump but isn't. The best way to tell is to wait to see if a breeding tube appears. The male breeding tube is small an pointed where-as the female tube is thicker and more blunt.
 
As to the behaviour you describe this is normal regardless of sex. Angelfish are not aptly named - angels they are not. Some can be incredibly aggressive where-as others can be quite layed back. It's the luck of the draw with them. You describe chest bumping and this sounds like it could be a heirarchy thing. If they are two males they will sort out for themselves who's the boss. Similary this could also be pairing behaviour too. For now I'd suggest you leave them be. They could get a little more aggressive if they are sorting out heirachy but unless you see one attempting to kill to other (and this will be obvious - one will pin the other down and keep attacking) I'd leave them be.
 
Hope that helps you somewhat. Sexing angels can be nigh on impossible

Thanks muchly =)

If you are desperate to know the sex for breeding purposes etc then you could ask on an angelfish forum I'm also a member of. It is a UK based one but there's members from all over the world. 
There's a guy on there who's great at sexing. He sexed mine for me and I'm trying to learn his method. I've not quite got it just yet but I'm getting there. You find it here uk-angelfishforum.org.uk  if you post a picture of both angels side on he'll have a look happily. It might take a while though as he's not around a lot. It's a very quiet forum