just a quick question!!

so uhm i just wanna ask because im simply curious and still wanna learn more!

Well on some of the yaoi mangas, the uke has an ex-bf who broke up with them and just ended up with a girl. Uhm in this case if that ex-bf just went out or dated the uke because he's simply curious and ended up liking the s3x only (he doesn't really love the uke or sumn) and in the end broke up with the uke because he's already bored. Then ended up dating or marrying a girl.

My question is, is that ex-bf considered or identified as bisexual?