In answer to the thread's question:
1. Stealth tactics, only deployed under cover of darkness, which should take the form of:
2. Climbing the back gate, before crawling on one's stomach to the garage. Covering fire should accompany such manoeuvres, and should be provided by one's best mate, in the courageous form of ringing the front door bell and then running away.
3. If rumbled and caught in possession of contraband goods, aver, with plenty of swearing and bluster, that one's credit card has been stolen by someone "who must be a chippy". Such an obvious lie lays the ground work for a second lie, which stands a better chance of being believed. Viz:
4. When the plausibility of 3 is challenged, as it will be, immediately admit wrong-doing, and assert that one needed said goods to complete "something for you, darling, since you're so clever, that if I'd told you about these purchases, you'd guess".
5. Having promised 4, seek a commercial workshop and beg them to produce promised object in return for huge fee and free beer.
6. Remind self that additional suspect purchases should be contracted only when "you're going to visit your mother, darling? That's wonderful! I know how close you two are. I'll stay here and do all the odd jobs that have been worrying you". Caution: do not gild the lilly; she'll suspect an affair. Thus, grit teeth, and call Mother-in-Law's by blower several times. Encouraging the dog to bark will prove that you are, indeed, at home.
As for epithets for SWMBO, the 'War Office' I think, can be bettered: since we are describing the thoughts and habits of women, I've always favoured the 'Foreign Office'. And maybe 'Elliot Ness', who was, after all, an Untouchable :wink:
JS