The way Gojo is going, he seems to be getting more emotionally away from Marin.
Meaning, if Marin ever confesses to Gojo, he would likely reject her or won't take it seriously.
And even if he does take it seriously, he would try to increase as much as distance as possible from her, because she would have ended up being his ideal doll by then, like his Hina Dolls. And like with the Hina Dolls, he would probably believe that he is only meant to look at them and polish then, not be with them (a craftsman doesn't keep their work to themselves).