( ͡° ͜ʖ ͡°)

Hey can anyone help me find this book? 
          	
          	Ok so, I know the book is a bl poly book( I don't remember how many people but it's more then 2) And I remember that it's a Omegaverse and the plot is something like how Omega's would be forced to leave their partner for their mate and get married to them. 
          	The MC is a Omega and has a bf and is scared (?) to find his mate(s) because of this rule. 
          	His mates are all really famous people too
          	(He meets the first one on a train I'm pretty sure) and only remember one of them who was a singer(or a rockstar)