Thanks everyone for the great advice :). He is being like this with his other owner and he doesn't get given a feed because he's quite porky anyway. I reckon I should try the lunging a see how we both get on. I will also have another word with him own :)
I have just got a Horse on part loan, he is very sharp when I ride him and I'm struggling with him a bit, he also spooks too and sometimes the odd buck. If I could have some advice on maybe trying to get him to settle a bit or If I may need to change how I ride then I would be very greatful...