I can understand the discomfort some might have if they assume the character are cheating on the other game's mc, the only time cheating of any form doesn't bother me is when the one being cheated on is neglecting, cheating themselves, or abusing the character that is cheating.
personally I'd assume they're just references to the other game and not the exact same character unless they reference events from the other game then I'd probably feel iffy about it, and obviously mentioning a partner would just make everything feel wrong
below is just me rambling because of something another commenter said
another comment talks about "multiple partners for women" making guys uncomfortable then a sarcasm quote about harems, and I've thought about it because I'm one of those guys that sees a women with multiple men as being inherently wrong but the other way around with a guy with multiple women as inherently neither right nor wrong
I came to the conclusion that it's probably got something to do with instincts, broadly speaking a male instinctively wants to impregnate as many healthy women as possible to ensure their bloodline and therefore the chance that another could possibly impregnate their mate before/instead of them makes them against the idea, whereas a woman just wants strong offspring and other women being with their mate doesn't prevent that so (atleast to a male) a male with multiple females feels natural and a female with multiple males feels wrong
there are ofcourse other influences such as culture, if monogamy isn't culturally enforced and your society is able to grow then stigma around multiple partners in general would reduce if not vanish entirely but I'm not aware of any where that has ever been the case as religion is often the main source of sexual restrictions in a society and most religions encourage or enforce a monogamous lifestyle and those that don't only allow for men to have multiple partners (and generally only those at the top of their hierarchy [kings, powerful warriors/military leaders, or religious leaders) likely due to my personal reasoning above