Baby boy name

Ok so I always said if I had a boy I would name him Jackson but the dilema is that my 2nd cousin named her son Jackson and he is only one. So I crossed that off the list and fell for Kaiden (not sure how I want to spell it). Anyways my s/o his 15 year old daughter got her first boyfriend this year and he broke her heart his name is Kaiden so he feels like it would be wrong. But I love it and I don't feel like I should change his name bc they only dated maybe a month and well if we can't name our kids after ex's of a family memeber we would be screwed. And I want to keep the name with a k because my daughters name and his daughters name all start with a k. Would I be wrong in putting my foot down?