It's not really leaking into another parallel world. It's just having its effect in more than the three spatial dimensions. Since the extra spatial dimensions are coiled up tight, the gravity effect is more or less lost there in a dimension we cannot interact with.
I understand that. However, gravity is spreading out into the ten or eleven dimensions currently postulated by physicists (I've seen as many as 64 proposed, but most stick to the lower numbers). If the effects of gravity were concentrated in the first four, or conversely pushed more heavily into the other seven dimensions (reducing its presence in the first four), one wonders what might be possible.
"Since the extra spatial dimensions are coiled up tight, the gravity effect is more or less lost there in a dimension wecannot[don't know how to] interact with."