I can’t remember what it was called, but I read this really good voltron fic once where Lance was an omega, but whoops no suppressants in space, so he starts going into heat. As the only other omega on board, Keith ‘helps him out’ if you know what I mean, and eventually Shiro, an alpha, got dragged into it, but despite the dynamics Keith was definitely the dominant one and I think he even topped Shiro.