About five years ago my best friend (known all my life) invited us to lunch. At the time we were living on the other side of the country but had family close-ish to her house. While there our other halves got talking - they've known each other about 20 years but are not especially close - and her DH showed mine a childhood collection of items that my DH is a specialist in (dealer). My DH offered to take said items home and research them. We next saw my friend again about a year when the subject wasn't referred to and ditto the following year, but both were family gatherings when we all had other things on our minds. Since then we have moved even further away (4+ hrs drive).
Fast forward to a few weeks back when I received a b/day card with a message asking my DH to call hers - he would like the items back and as they'll be in the area 'soon' we could meet up.
Stupidly assuming DH knew exactly where the items in question were I suggested he dig them out and call friend's DH at which point he looked a trifle sheepish and said he 'thought' they were in the garage. Now, after buying this house in late 2014 we moved a garage-full of stuff from the storage unit we rented when living at our previous house, so our garage is pretty chocka. I offered to help DH search - which took several days - but to no avail. We also went through cupboards in the house - it's a restoration project and we're living in a building site at the mo, so I thought they were just mislaid - again, no joy.
At that point I started to get suspicious of DH - he does have a bit of a tendency to be a little economical with the truth (nothing really bad, just 'white lies' supposedly to protect me/other people from getting hurt......) - and asked him if he'd either sold them intentionally or inadvertently perhaps? He was adamant that he hadn't and started suggesting our (very expensive and otherwise wholly reliable) removers had nicked them. I should point out here that these items are of no intrinsic, only sentimental value and could probably - with some effort - be replaced.
Anyway, he initially said he'd call friend's DH, then went quiet and when reminded a couple of weeks later he'd (conveniently?) forgotten all about it 
Now several weeks have passed and I'm feeling awful - my friend doesn't have our landline no and we've both changed mobile numbers since we last spoke. We no longer do FB after we were stalked by someone relating to our business and we don't know when their planned trip this way is. I'm worried that my friend and her DH will turn up on our doorstep when we least expect it. Worse still it's her b/day soon and I now feel I can't send her a card without mentioning the subject.
I feel DH has put me into a difficult position that threatens to undermine a lifelong friendship.....what should I do and AIBU?