I think it’s absolutely normal. My wife has male friends, and she talks with them, and spends time with them, not in my presence.
If you feel it’s inappropriate, then, IMO, you’re somewhere between old-fashioned and controlling or paranoid (or perhaps a member of a conservative religion).
Turning this around: @thescrr - if you are a male, do you feel that it’s inappropriate to have female friends with whom you talk and do things without your wife?
FWIW, I’m married; my wife has male friends with whom she does things, and I have female friends with whom I do things – for that matter, the two people whom I consider to be my best friends (other than my wife) are both women.