Both you and Fox like each other and are well aware that you both feel the same, but you aren’t dating each other because there is an age gap between you two. Even though you are both full grown adults Mulder still feels iffy about dating you because he doesn’t want people to think that he’s taking advantage of you or something horrible like that because you’re younger, even though that is obviously not the case. So, for now you guys are only friends with feelings for each other.