Fingering her ass???

Guys this one time we were kissing and doing foreplay in bed and I got Sandra to take my precum on her finger and slip her finger in her own anus. Is that normal? I was shocked at the time when she did it.....I asked her to get more precum and rub it in. I was stroking myelf off watching her finger her bum.
Then I said i would love to taste her finger. I asked her would she let me have a taste.
she pulled her finger down and out of her ass and held it in front of me, actually I did, just opened my mouth and sucked her finger immediately before she changed her mind. is that bad?
i didnt even take the time to look at it closely i wanked so hard sucking on her finger, it didnt smell pleasent but made me rock hard. do you think most men would have done the same as me? She doesnt let me do anal sex ever really, just tried it a few times in the first few years.
Do you think that was in any way slutty at all guys and gals, or is it pretty standard for most wives these days??
Please let us know your views in the comments and perhaps give a 1-10 rating for kinkiness.