Who is BU here?

[IPlayMyGuitar]

Annie and Bettie are close relatives and live a few miles part.
When Annie is out doing errands, she will sometimes drop in to see Bettie unannounced. Annie does the same with Bettie, so calling round unannounced is not a problem.

Annie called round to see Bettie, but nobody answered the door. She went round the back of the house into the garden to see if Bettie was in but had not heard the bell. Annie feels that as they are close family it is reasonable to go round the back to check if they have not heard the doorbell.

Bettie feels that if they do not answer the door then Annie should know they are either not in or do not want guests and that going round the back is intrusive.

YABU - Annie is right. Peering though windows at the back it out of order.
YANBU - Bettie is right. They are close family and she thought Bettie hadn't heard her at the door.

This.

Neither is right / wrong.

The person who doesn't like it needs to tell the other person, and that is the end of it. In some families / neighbourhoods it would be very normal to go round the back door. But equally, in others it seems intrusive.
Annie and Bettie just need to make clear to each other what each of them is / isn't comfortable with.

before my Nan went into a care home, I would sometimes go round the back. It was reasonable. She was older, lived alone and we were suspecting (correctly) the beginnings of dementia.
in instances like safety concerns, of course it’s okay to go round the back. Perhaps trying a phone call before popping by might be good

Luckily we have a locked back gate and a ring doorbell but quite often I will close the blinds at the front and pretend I’m not in: as an adult I don’t feel I need to answer the door if someone comes round. And if someone did peep through my window etc I’d be absolutely fuming!!!
Unless there is a reason you’d be concerned and couldnt contact them on phone then it’s really rude.

you can only hope the nosey cow catches them with a huge strap on riding the local postman or such and gets a short sharp lesson on invading privacy

quite often I will close the blinds at the front and pretend I’m not in: as an adult I don’t feel I need to answer the door

Made me smile. I would have thought as an adult you would open your front door (unless your're actually busy) and not hide in your own home - makes me think of a dated Ken Loach type film with familes hiding from the rent man. It was when I was a child that I was told "I'm popping out so don't answer the front door!". 😀

Bettie needs to learn that people differ on what they think is or isn't appropriate. She should hide on the stairs until unwanted visitors have gone away. A ring camera also helps to confirm they have given up and departed.

If Betty is not elderly or vulnerable then Annie should not have gone around the back if it was an unplanned visit. If I pop over to my parents ( in their 80s) and the car is there I would investigate further if the door was not answered.
My brother is in hospital atm but if I had popped over to his and he didn't answer the door I would assume he was out or didn't want visitors. I would not go around the back.

I'd like to know what Bettie was up to that made it inconvenient for Annie to pop in, when normally she's welcome?

I think even with close relatives it's polite to call first.

I thought Annie was going to catch Bettie shagging the Gardner 😅 Tough one, I'd go peer, but also I'd text first to say I was popping over. Equally I'd answer my door and not avoid so I wouldn't be bothered by someone peering either. I think each to their own, there's no hard and fast rules.

Maybe she was having a particularly stubborn shit, maybe she was shagging the postman, maybe she had a gerbil stuck in her arse... sometimes uninvited guests should just accept that the door will not be answered and leave.

You could easily open my back gate and walk round to my back door. I would be very surprised and somewhat taken aback if anyone did that, even a close friend.

EXCEPT in the summer when I am in the garden and don't hear the doorbell, then if a friend opened the gate and called out hello I wouldn't mind.

But if I went round to my mum and dads and car was there and no-one answered I would do some peering through windows etc to check that they weren't lying on the floor. Not sure I'd go into the back garden at this time of year though.

So I am on the fence here. But now that Betty has said don't do it, Annie must repestc that and not do it.

I'd say no one is wrong? I can see why Annie thought it would be ok to go round the back. But it wasn't which is fine. If I was Annie I'd stop calling in unannounced.

Team Betty.

Could be worse though, Annie could have started throwing stones up at the window like my grandmother does when we don't answer the door to yet another unarranged visit.

In my family it would be very common for my sisters and I and parents and nieces and nephews to do the popping round to the garden thing if they expected us to be in and we didn't answer. This wouldn't extend to peering through windows unless they actually saw us in passing( and we genuinely hadn't heard the bell). So it relates to a category of people( close family) who are outside the norm. I wouldn't do it to, or expect it from other people but it's acceptable within our group.

The real question is, is this something which is normal for A and B to do and something they have done in the past?

If it is then is very much like my own situation, so whilst sometimes annoying, I think it's fine.
If neither of them had form for garden visiting then it's strange and they shouldn't have done it.

I wasn't in when she called - so wasn't ignoring her. The first clue I was out was that my car wasn't on the drive. The second clue was I didn't answer the door.

She set off the external alarm sensors (we were burgled recently so now have external sensors covering the outsides of the house). So the alarm went off on my phone, I thought shit we are being burgled, looked at the cctv and saw her trying to get to the back of the house. She says she thought she heard DH in the back garden, which is highly unlikely as he a) wasn't there to make a noise and b) you would not be able to hear anything from the back anyway.
When I told her I thought it was out of order, I was told it is perfectly reasonable to go into a family members back garden if they don't answer the door, and that she would not discuss it further with me. She's in a huff over it.

I'm thinking not answering the door shouldn't result in people going round the back to double check if I'm really not in. Even if they are family.
I WFH and this is not the first argument we have had over boundaries.

The only time for peering through other people's windows is when you are concerned for their health. You should NEVER take it upon yourself to have a good gawp through anyone's windows no matter how well you know them