Will having someone else have the same position at your school decease your chances of getting into T20s?

I have recently started a new initiative (starting something on my own and leading a team) and my BF asked to be a “leader” with me. When I rejected him, he got mad and said im gate keeping and that there’s literally no harm in adding the same leader position in the extra curricular section of common app. Am I wrong for not giving him the role as his GF? I just feel like it should be an obligation and he keeps saying I’m trying to “sabotage” him for not helping him out.