Hmm, this is interesting. My spouse of 22 years has been courted by several men and I have had to point it out to him. For hubby it's that he has had trouble identifying with "macho men" which is the expectation where we live. He is a gentle loving man who kisses and hugs and that is not a real man here. He even wears night shirts. So he has had shame about his own sexuality based on what the "real men" have done, do. Hubby is not homosexual. He is hubby. As for yours, it is hard for men to have close male friendships at times. The kind that a woman might find easier, hugging, crying, kissing, sleeping side bu side for solace and company. Culture makes a big difference.

I would just speak with him a lot about this and keep the dialogue open. Also, explain that if he really finds himself in a place where there could be intimacy with another male to protect himself and you as well. You deserve at least that.