Matilda still sometimes does open mouth kisses, but only when she really loves someone

As far as biting is concerned, Matilda has done it a handful of times & like you said, most times its just testing out those teeth to find out what happens.

When I teach puppy school, I often tell people to let their pups know everytime their teeth touch their skin, so do what a puppy does, which is let out a high pitched "ow!" so I tried that on Matilda (I was taken off guard because the first time she did it was 14 months) and yelled ow!, she laughed but the next time I did it she got a bit concerned & she's not tried to bite me since, once in a tantrum out of frustration, but I did ow & she stopped again. So I dunno if its just me, but afterwards I tell her that it hurts and ask for a kiss to make it better, which is always indulges me with.