Well then you should know why.
House of X hinted at Wolverine sleeping with a married woman with kids, while said married woman's husband is out there doing much the same. This is what kick-started this shitty speculation.
Then X-Men showed that Wolverine's now for some reason that hasn't been explained living in the Summers household, a place where Cyclops, Marvel Girl, Havok, Vulcan, Cable, and Rachel live. Wolverine's the only odd entity there because he has no familial relation to any of them.
Then the same X-Men issue showed that Wolverine's room in that house is right next to Marvel Girl's. Marvel Girl doesn't share a room with Cyclops, but has her own room that is joined to that of Wolverine's and Cyclops'.
Then you've Giant Sized X-Men you've Marvel showing while holding hands with Cyclops and kissing Wolverine in the cheeks, before carrying on her mission.
Then you've Cyclops inviting Wolverine, while both of them are in Cyclops' home, for a family get-together at the beach. Something that prompts Wolverine to fantasize about Marvel Girl in a bikini.
Then you've MARVEL own website making an article about Krakoa's new couples and what they're up to, and when it comes to Cyclops and Marvel Girl, they cite that the couple are residing in the moon away from prying eyes to live their life they way, and then a blurb about how weird it is that Wolverine is also there.
And finally you've the editors joking during a panel about Wolverine having two dicks, one that he uses to fuck Cyclops, and another that he uses to make love to Marvel Girl.
So i can't fault others from speculation about the situation asking themselves if Cyclops and Wolverine are gay, or if Cyclops is a cuckold sharing Marvel Girl, or whatever. Because it's clear that's what MARVEL want people to do.