Here's why:
* Their relationship has been on-again, off-again: They have had a tumultuous relationship, with periods of romance, separation, and even heartbreak.
* Obstacles to marriage: Several factors have prevented them from officially tying the knot, including:
* Rogue's powers: Rogue's ability to absorb others' powers and memories is a significant challenge in their relationship, and it could pose risks for a potential spouse.
* Gambit's past: Gambit's history with the Thieves Guild and his past as a mutant criminal has also been a point of tension.
* Other relationships: Both Rogue and Gambit have had other significant relationships in the comics, adding complexity to their shared history.
However, there have been instances where they have come close to marriage:
* In the "X-Men: Age of Apocalypse" storyline, Rogue and Gambit were married and had a child.
* In the "Ultimate X-Men" universe, Rogue and Gambit had a very committed relationship and were even engaged at one point.
Ultimately, their relationship has been a rollercoaster ride with many twists and turns. Whether they will eventually get married remains to be seen, but it's a popular fan theory and something many fans would love to see.