Gosh Djoko....black is your color BUT it doesn't look good on you, sorry

I sense you're going to be getting an increase soon. Better get your act together

I've been thinking of ways to help better the bond between you and Djoko. And I'm not saying y'all have a bad bond. He just needs to try and depend on you more from time to time. If you're BF isn't around, testing proves to be more difficult. gotta try and fix that.
How do you feel about YOU being the main caregiver for Djoko(you may have already tried/or are doing this...apologies in advance). He already has a strong bond to your BF so, lets try to make Djoko "forget" that your BF is the apple of Djoko's eye.
Indoor cats are supplied everything they need to survive by us. Their lives depend on us. Cats tend to bond with the person who is their primary caregiver. Be the source of all of Djoko's needs.
I have 10 cats total. I'm their main caregiver. They seek me out before my DH for their needs including attention.
Having your BF back off a little could make Djoko seek you out for his needs.
Have you tried having your BF hold Djoko for testing while you do the poking?