How well does the flavour hold up after pickling?
That is a very interesting looking pepper. Chupetinho = Chupetinha (Pimenta Bico) ? http://www.thechileman.org/results.php?find=chupetinha&heat=Any&origin=Any&genus=Any&chile=1
Above says they are mild, is that your experience? A cursory search turns up nothing on seed availability. I realize you are in Spain; however, do you have any information on a seed source or difficulty on locating some here in the U.S.
Nice job on the pickled peppers, they look very fresh and tasty.
Update: Tradewindsfruitstore.com has them listed but the description certainly doesn't match what I'm seeing from your posting.
Chupetinha Pepper - Capsicum chinense
"A rounded, cone shaped pepper up to 3" long. Ripens to red and has a mildly hot flavor. Little known, native to Brazil. Name translates as "small rubber nipple"."
I remember when I first saw Potawie's amazing mild Chupetinha plant:
The mildest similar plant I managed to get seeds of is a Biquinho. Perhaps Potawie can point the way for you.If by chance you want a productive non-hot C. chinenses then chupetinha is a good choice although they are quite seedy pods and quite small.
Potawie- Chupetinha 2010