Get him a really crap bike to use that wont get nicked.
They'll nick anything on wheels round here if it's not locked... Last bike he had nicked was one of the granny shopper bikes I loan to punters who have bikes in for repair. Even that didn't stop the inevitable..... What's most annoying is he didn't tell me till I noticed it was missing and wondered why he had locked up his mums' Dutch shopping bike which would probably also have got nicked by this time next week.
Anyway... I'm a total bastard so I've taken
1) £350 off him for the second bike
2) Told him that he's not getting another bike till he's worked off the money for the parts to build a new one.....
Which resulted in a major attitude outburst which resulted in
3) Confiscating the I-pad, his laptop the PS3, PS2 and removed his gaming user profile from the house desktop.
Wife thinks I'm being too hard on him.
Good for you. Ok, so you've taken his stuff, but on what terms? You have to have terms as you are
going to give it back, eventually. So you need to say I'm taking this for two weeks, and nothing other than arranging world peace will get them back sooner. If you fold, don't bother trying jack again, and you need to say three weeks to the wife and meet at two in the middle and a united front.
I manipulated my parents something chronic, playing stupid, lieing, stubborness, sidestepping, distraction - I always managed to lead them away from actually doing anything, mean really. (I never did anything truly serious or harmful to to anyone mind)