Cucumbers

According to Unwins it's an all female variety, so there shouldn't be any male flowers to remove..
https://www.gardenhealth.com/unwins-cucumber-tasty-king-f1

Marshall's say differently and have this under their "How to" and "Aftercare" headings:

"Do not remove male flowers (those without a fruit behind them) as these are necessary for pollination of the female flowers."

This old, unfortunately unanswered, thread on this forum suggests that pollinated fruits are bitter:
https://chat.allotment-garden.org/index.php?topic=43074.msg506861#msg506861

Very tricky one this, and not a situation the suppliers should have put you in - if you remove all the male flowers you risk getting nothing, if you don't there's a risk any cukes will be bitter.

Hopefully someone will come along who has grown this variety and knows the answer - I'd probably just wait and see, and if the fruits are bitter, remove all subsequent male flowers.