We accepted a 15 year old Foreign Exchange pupil and when reading up on his personality it said he liked practical jokes and generally having fun. Just like DH so DH said he'd play a few on him once he'd got settled in. So he arrived on Saturday and thankfully DH left him alone to chill out, Sunday he started being a prat. First "joke" was the lad was in the bathroom and DH catapulted himself at the door and started screaming and shouting about needing to wee banging on the door and making growling noises etc. I went mad because there was a bang, the lad had obviously had a fright and dropped something and then wouldn't come out of the bathroom for ages. DH eventually (after he'd finished crying with laughter 
spoke through the door apologising but adding "that's how we ask for the toilet in England". FFS
I had a word with DH saying that was way ott and not to do anything else as he's spoiling the lads trip. So this morning he filled a bag FULL of plain bread slices, poured a bit of hot chocolate in it and then stood on it and squashed it up etc and gave it to the lad telling him it was his packed lunch for the day and that was how we did packed lunches in England. The lad was mortified but took it anyway, when I realised I shouted after him and gave him money for the shop. Tonight he's planning to scream manically at the TV everytime the adverts come on. I've told him if he does I will seriously be pissed off and he says he's just trying to have a laugh. The lad is spending all of his time locked away in the bedroom obviously wishing he hadn't bothered with the exchange. I feel so sorry for him and cross at DH.