Bentley is being a typical boy and being very clingy of his mommy. Nikko is the same way, he prefers me over my fiancee. If my fiancee leans in to give me a kiss while we are on the couch, Nikko jumps right in and wiggles his face in the middle
and licks me first!! When I am not home, they bond though and Nikko loves his daddy, he just prefers mommy. I think your bf and Bentley need some guy time alone to bond. Give it some time, I am sure Bentley will open up to your bf.