hmm that's a strange one but not unheard of. Does it taste good? What kind of cucumbers are you growing? The first couple are sometimes a bit wonky but should still be good to eat.

The cucs are called Telegraph, and grow up to 11 inches and are rather thin, but nice and crisp. They’re fine as far as I know but what do I know - I’ve little sense of taste or smell - sadly. The 2 plants are 7 ft tall just now and I’m now growing them across my porch ceiling.

Are they tasting alright/useable? I find, growing courgettes & cukes outdoors, they need checking on daily. Any that don't feel firm & crisp entirely along their length get snipped off. It's that thing where we want them to produce loads but the plant just wants to set seed. Just a variation on deadheading flowers...

I have grown telegraph many times over the years.
but I got fed up with having to remove the male flowers. if a flower gets pollinated the fruit is bitter compared to the female flowers that produce a cucumber when not pollinated.
I go for the petita type now that produce fruits about 6" long. they keep very well and a 'half' sized one lasts long enough for us to eat it before it goes off.

as for your extra leaf its not unusual . just snip it off.

I forgot altogether about the problem with pollination and My daughter and I have so far eaten about 8 without a problem. But take little notice of me as I said I have little sense of smell or taste. Daughter however has excellent sense of smell/taste and describes them as really nice and crisp.