The tension is still there, it's just changed slightly. Naturally, Bryan and Caleb want answers from Calvin, and Diego must realise this. Trying to stop the boys from meeting Calvin Diego will, unintentionally, make it worse making him as guilty as Bryan for creating the tension. I agree that allowing Calvin to see either, or both, of the boys, is likely to create problems, but at least they will have a better chance to deal with the problems better. Any meeting between Calvin and the boys needs to be supervised and done in as safe an environment as possible. What we still don't know is what Calvin's intentions are, but it is safe to assume that they are not good as Calvin is a selfish prick who only wants to use them for his own ends.