How do I decline this offer without seeming critical?

[HenriettaPootel]

Taking DS to a local tourist attraction later in the week. Next door neighbour says she will lend me her membership card and I just have to pretend to be her to get in free (no photo ID). I don't want to do this on moral grounds (bit of a bugbear of mine - my MIL does this sort of thing all the time and I hate it). But how should I say no? If I tell her I'm not comfortable with it, then I'm implicitly questioning her morals/integrity over making the offer. If I say yes please then pretend I've used it when I haven't (or if I say 'I'd love to but I don't dare' or some such), then I'm pretending to condone something that I really don't. Any advice please?

Brief but polite - 'no thanks, we're fine'. Or sneak off without it when she's not looking.

I would say another friend mentioned that the venue sometimes ask for a form of photo
ID as back up .. And that it would be too risky.

I've been in this position. I just said, thanks for the offer but I'm happy to pay the entrance fee. If it's a charity like a zoo or National Trust or summat then you can say you like to support their work.

Ooh, you guys on Etiquette certainly answer quickly (I guess that's just polite ). Yes, I guess a quick 'it's fine' or 'I'm happy to pay' should hopefully cover it. And horsebiscuit thanks, I hadn't really thought of putting it in terms of 'they need the money'. It's not a charity as such, but it's still a historic property and, I would argue, a good cause.