The german term "spötteln" means -perhaps- a light version of "spotten" for which LEO.org gives english words like "to jeer", "scibe", "scoff" or "taunt".
But "spötteln" has something much lighter than "spott", for me it has - without really bad-will- a lightly amused state of mind in the speaker ... difficult to say...

Q: What would be an enlish approximation to this?

FOR THE request in the comments:
"Vater hatte stets die Angewohnheit, über die Freundinnen seiner Söhne zu spötteln"

or

"Sogar in Zeiten in denen es ihr wirtschaftlich nicht gut ging, brachte Oma es fertig, stets eine leicht spöttelnde Art im Gespräch über die alltäglichsten Dinge aufrechtzuerhalten".

DeepL makes the proposal:
"Father always had a habit of mocking his sons' girlfriends"

"Even in times when she was not doing well economically, Grandma always managed to maintain a slightly mocking manner in conversation about the most mundane things."

My take: "mocking" seems to be too sharp here (in my understanding); the "spötteln"-behave in interpersonal communication would not use really sniding jokes (as well: in my understanding)