"Aleister Crowley maintained that the task of his sexmagical organisation Ordo Templi Orientis (O.T.O.) was "to restore Christianity to its real status as a solar-phallic religion." ... [a bit much for me]. He went on to say "Ultimately in the O.T.O's sexual magick everything came down to semen - more recently likened to a computer hard-disk pre-formatted to be loaded with software and used at will. Crowley: "The industrial use of Semen will revolutionize human society"; journal 8th August 1923."
I also cherish the opening line of John Varley's book, Steel Beach: "the penis will be obsolete in five years." That doesn't have anything to do with the immediate discussion, but I love the quote!
I'm aware that many male readers are squicked even by second-hand contact with semen, without any M-M contact. Indeed, even contact with their own can be upsetting. From real-world experience, though, I've found that women can find it incredibly erotic when their partner is willing to taste himself, even after a blowjob. It might be ideal to have a snowballing as well as a creampie code, but the latter will have to do.
You will find the above acts and warnings in many of my stories. Consider yourself warned, and then invited cheerfully to read.
The contact above is in the context of more or less vanilla sex. If I use the creampie <u>and</u> the magic code, don't be surprised to find Crowley-type magick (magick with a k meaning not sleight-of-hand, but something that changes reality to fit the will).
I don't see a need to have warnings if there are gay male characters that have sex not in the story, and even might provide semen for rituals such as above. Still, there are times when M-M sex has a role for the characters. I'll use the MM code in such cases, even if fairly mild.