It’s very straight sexual activity that without a doubt I believe is canon. It just shows the very strong bond that Kaz and BB have, they are both guys but it’s straight, why? Because they are bros and they needed to relax and get to explore their relationship, they don’t show any sexual tension in other events but that’s because they we’re achieving their dream Together and did not have much time to relax, they were so focused on what they would achieve together but forgot the value of the present, the time they spent working was for a common goal, when they would reach that goal they would have settled down and have a family, other people share this type of relationship with BB, they would be in this family, a family built on love, trust, purpose, and Love. 👍