Warning! Spoilers to X-Force #20 below!
Although they switch from being friends to enemies constantly, Wolverine's latest battle with Deadpool is actually thanks to the X-Men and not Wade for a change. While handling security for the highly anticipated diplomatic summit the Hellfire Gala, Wolverine discovers Deadpool trying to sneak in through the ocean, annoyed that his invite must have been lost in the mail. Despite X-Force's handling of the situation, the entire ordeal is the X-Men's fault who let personal grievances justify the denial of a diplomatic representative even if his presence would likely lead to him being asked to leave.
With the world still on edge after the mutant nation of Krakoa was established, the X-Men along with their forgiven enemies and next generation of mutants wanted to create an event that celebrated the emerging mutant identity while also helping to smooth out their diplomatic relations with other countries. The Hellfire Gala was announced where famous mutant heroes debuted eye-catching new outfits and invited ambassadors ranging from the U.N to the Avengers and even Latveria's Doctor Doom. While the guest list included famous celebrities such as Eminem, X-Force agreed to do security for the event complete with psychic scans, Krakoan flowers on guests' lapels, and its members constantly on alert and patrolling for any unexpected visitors looking to exploit the event or attack their famous hosts.
In X-Force #20 by Benjamin Percy and Joshua Cassara, the guests and the event is going well even if others like Avengers Iron Man don't want to play by their rules. Noticing movement on the south side, Wolverine prepares to attack someone stupid enough to crash their party and that person is Deadpool. Having traveled by sea, Deadpool's rubber duckie floatie and harpoon gun only further annoy Logan who feels Wade sees this as crashing a party instead of what that could mean for Krakoa and its people. Wade seems temporarily annoyed at not getting invited and then peppers Wolverine with questions about what to expect inside as he exploits their mutual healing factor to his advantage. Although he is eventually neutralized with the help of Domino, the X-Men soon realize they have bigger problems to deal with.
Like many Marvel heroes and villains, the X-Men do not like Deadpool and will only work with him if necessary, finding his humor and antics to be annoying and unnecessarily destructive. But in this case, they were actually in the wrong as Wade is the King of the Monsters, the kingdom currently located on Staten Island and thus making him a foreign political entity worthy of an invite. The X-Men probably feared that inviting Deadpool would create a situation, as his reputation proceeds him, and the Hellfire Gala needed little to no problems. Their decision to not invite him was likely personal since they've recently clashed with Wade over his non-mutant status after he managed to sneak onto Krakoa in an unorthodox fashion. Since he's gatecrashed before, X-Force should have made sure to have been prepared for Deadpool because simply stranger things have happened whenever they gather.
Although he began as an enemy, Deadpool has been nothing but an ally and supporter of the X-Men throughout the years yet they simply won't invite him because they didn't want him hurting their chances with new, powerful friends that'd benefit them in the long run. Wolverine didn't want to fight Wade but his responsibilities to X-Force and Krakoa made them enemies yet again, proving that despite their new status quo, the X-Men still make mistakes that come back to haunt them. Although the Hellfire Gala appears to have taken a turn for the worst at the end of the issue, one can only imagine what hilarity may have occurred simply by inviting Deadpool in the first place.