Ladies, I understand the male/female dynamic in most situations but am stuck on male/male.

Situation, My longtime friend is in town for 2 weeks for work/leisure and she brought her SO. Trying to be a good area host I invited them for dinner and for local activities with myself and my SO who is very RP.

Issue, my friends SO complains. A lot. About everything. But only in presence of my boyfriend. It's not the usual playful/competitive banter to see who is more alpha because it's really no comparison. My SO gets along with other alphas and usually gets respect from betas.

Question, why is this instance so different than anyone else we've met and what is my duty to help him and us maintain frame and poise these situations? I do not publicly disagree with my SO but is it my place to say something to the 'boy who is the princess and the pea'?

Any insight is greatly appreciated as I am stumped!

Edit: thank you for comments. I will gently mention it to my friend but other than that I will say nothing. I'll chalk it up as practice for when I have dealings with people I don't like. An exercise in composure to say the least.