Just talkk to your BF ughhhh, communicate PLEASE
I think I kinda understand him, he already caused so much emotional damage to his bf with his insecurity and all (from the start) that he wants to show him his good sides. Maybe would it be better for him to be successful in the project and then confess everything to Juha, a way to grow his confidence and maturity by himself :)
No lube, no protection—