To have tied myself in knots about this?

[MortificadoMarkTen]

Long story but basically housemate 1 was away yest. Other housemate (2) and I were in. An object of housemate 1's was downstairs and had been for yonks, so I popped it upstairs in their room. Think they have taken offence and blamed housemate 2 for going into their room/judging the state of it - hm 2 is also confusingly being off with them but no one knows why. Need to fess up as don't wasn't other housemate getting blame but don't know what to say (they haven't spoken, I mutely implied I hadn't done it in the heat of moment and now feel terrible!)

Just tell them you thought item should be in their room so popped it there, you don't know why you didn't just tell them. Job done

Just pretend you misheard. Tell H1 you're sorry you thought they meant x when actually they meant y had been put in their room.
You moved it as you were tidying up and just thought you'd put it out of harms way.

If it's something that doesn't really belong in the living room or is overly on the way / trip hazard then fair enough but if it's their choice to keep it there then I don't think you should move it. Speaking from bitter experience of a housemate who took against me keeping my laptop in the living room tucked away on a coffee table she never not once used

It was a few pairs of heels that had been in our v small entrance way. Maybe aibu...

There's only really enough room for one or two pairs of everyone's shoes and we have talked about this a few times but hm1 doesn't seem keen to keep in room?

Heels in the hallway that you've talked about, she's lucky you put them in her room & not the bin. If she gives you any grief for going in her room, tell her to stick to the rules & it won't be necessary...

Was it her who commented on your dress?

You could have put it in front of her room. YWBU to open her door. Now be a big girl and take responsibility for it instead of cowardly pretending HM2 did it....

"Oh, you're talking about those shoes! Sorry, it was me that moved them, I fell over them coming in and popped them in your room because I didn't want to accidentaly damage them. Didn't realise they were the ones you were talking about earlier, sorry about that mix up!"

Just fess up and tell her you did it, and if she asks why you didn't admit it when she asked earlier, just pretend there were crossed wires and you thought she ws talking about something else.