I like watching gay porn (and straight) but when I cum I get turned off real quick is that weird?

New to this and this is the first time I'm talking about my sexuality. Like when I'm horny sometimes all I want is to have sex with a man ready to swallow the whole 9 yards. But when I cum (while masterbateing I should have said that earlier) I'm done don't want anything to do with men and then it just seems so weird. Like my desire to be with men is lost. Like I would fantasize about having a bf then just not.I should mention that I have accepted that I'm bi.