Don't think that I ever really have, maybe i've left a bullet in the bathroom or others drying out. My OH stuck my suction cup one on the bathroom wall on purpose to embarrace his mates when they came around becuase they squirm when it comes to sex although they (aparently) have had sex... Not with each other though.
My cousin was given a beginner's bondage set and a cute little beginner's dildo as a hostess prize for hosting an **removed by moderator** party in her house one Saturday night. She got quite drunk at the party and instead of putting them away properly, she just tossed them haphazardly onto the top of her wardrobe. On Monday, the Virgin Media lads came out to install cable in her bedroom... and the toys fell off the top of the wardrobe onto their heads. They thought it was hilarious and teased her something rotten the whole time they were there.
I've never left anything anywhere that someone could find it, but I did have an embarrassing incident once when my dad was building furniture for me in my bedroom. We were on the floor in front of my bedroom cabinet, reading the building instructions for the furniture, when the entire bedroom cabinet started rumbling. Clearly something in there was vibrating. I'm terrible at showing everything on my face so I'm sure I must have looked horrified, and quickly fumbled my top drawer open to turn off whatever it was - only to realise that it was my mobile phone, sitting on top of the cabinet. It was too late, though - the way I dived into the top drawer made it clear to my dad that something was in there!
I tried to cover my embarrassment by saying "It was just my mobile phone" and he answered in a really snooty judgemental tone "It BETTER just be your phone." I was only about 21 at the time and mortified. If it happened now, I would challenge him on that comment. I'd still rather my dad not know about my toy collection, but if he said something that insinuated there's something wrong with owning toys, I'm old enough and confident enough that I'd stand up for myself.
Left the large box my toys are In sitting on my bed with it half open aa few times and my mum has caught a glance but I just skirt round the curiosity if she ever asks. Sure she knows when I get anything from LH as it's one of a very few select packages that I never open in front of her,
Normally Wise enough to put the box in a cupboard and certainly remember to do it when anyone like my sister is coming over as she often glances in my room if i'm there or not .
i once left my glow in the dark classic wand vibe out under a lamp in my bedroom to charge up the glow in the dark in quite plain view and i've left either of my bombshell balms or sex toy cleaner in the bathroom numerous times after fogetting to put them away if any one has noticed they've not said anything.... yet
I had to sleep in my sister's room one time as my room was being painted and I usually keep a bullet vibe handy in my pillowcase. One evening I went to bed and noticed it wasn't under my head as usual so I had a look round for it, I couldn't find it anywhere! The next morning I went uni and then when I came back my mum had stripped and washed all my bedcovers. She said "Oh I found something of yours in your sister's room, it's a good thing she didn't find it. I put it in your bedside table." I am mortified and rush to my bedside table where she has put it, I died a little inside. It was only a teeny tiny bullet and I hadn't used it in a couple of days but I was still embarressed. It could have been worse - I always keep telling myself at least it was clean :) And she hasn't told anyone else as far as I'm aware!
I have been looking through this community since my first purchase and have not come acros anything as funny as this thread before! Have never left a toy but my only just mother in law found one of my spandex costumes on two occasions but me and the wife passed it off as her swiming costume some how...
My mum decided to organise my wardrobe at home so when I came back my Mrs Clause and other babydolls were neatly folded...I was a bit embarrassed about that and am now very careful about leaving any costumes and toys there in the locked draw! I don't think she'd mind though, I've told her I test "lube and condoms and things" for Lovehoney, but the last time I was there I couldn't find my wallet and when I asked her if she'd seen it she was like "Have I seen what? Your wand?" So I guess she knows....
I am terrible for leaving things out. My hubby usually does a quick sweep of the house before anyone visits... except for his pornographic novels which have pride of place on the book shelf.
Got a new toy had some fun times as you do when you buy a new one. Went to the bathroom to wash and clean it. Door bell rings as its elections day (I remember it vividly you see), and we had council people reminding us to vote. Forgot completely about till I hear my mum stumbkles across it. Was not a pleasant day. 
So far (touch wood) I have been fairly lucky.. I although took a picture of myself in a mirror for Halloween (dressed up) and sent it to multiple people including my mother. In the morning I was browsing the photos and in the corner of my image I spyed one black cock ring on a bedside table.. I have no idea if anyone really recognised it but doh!
When I was with my last girlfriend, we went away one for a romantic weekend in a fairly posh country hotel in the Cotswolds. We were feeling fairly amorous most of the time we were there, and early on the second morning, we had rather lewd sex almost as soon as we woke up, with a strapless strap-on - I'm pretty sure it was our Tantus Feeldoe.
Afterwards, we realised breakfast was nearly over, so we quickly straightened ourselves out, threw on some clothes, and scurried downstairs.
Post breakfast, we went for a little stroll outside, and that was our mistake, because when we returned to our room, we'd found the maid had been, and (can't think of a synonym here) had done our room.
At first we thought, how nice, to see the bed neatly made up and so on, and then the penny dropped - we realised what the maid would have witnessed when she came in - the bed a morass of tangled, wet, smelly sheets, with the pillows all over the place. It would have taken little imagination on its own to work out what had just been happening.
And then we saw it - our dildo, delicately placed in the centre of the bed. We'd just dumped it somewhere when we'd rushed downstairs. Poor maid; I shuddered when it occurred to me that only an hour previously one end of that dildo had been up my bum, and the other end in nearly as delicate a part of my girlfriend.
We spent the rest of our stay studiously trying to avoid eye contact with any of the staff...
In one of the other shared houses I lived in, I might have left one in the bathroom by mistake, and I'm sure I left some toy cleaner in there at one point or another. If I did leave a toy there, I found it and cleared it away before any of my housemates came back. The cleaner might have been out for longer, but if I recall, it was on my shelf, so no one may have noticed. If they did, they didnt' say anything.
Once my friend needed to borrow a pen from my purse so I just waved him off and told him to dig around and find one and he pulled out a pair of handcuffs I'd forgotten about from the weekend. He actually accused me of being an undercover cop until I showed him the little stamped logos on the side. Definitely not police issue!
Just now  I was running a bath and put my glass butt plug in the get nice and warm. My dad knocked on the door to use the toilet before I got in the bath. I shoved my other plug, lube etc under the towel but forgot about the plug in the bath! I didn't realise until I was outside the door waiting for him. He didn't say anything but I'm pretty sure he saw it because he said my water was running a bit cold, so he obviously looked at the bath! I didn't even have the bubbles in yet so it was really obvious! I'm in the bath now dreading getting out...maybe I can just stay here forever!