Um, just a bit on the terminology:
Heterosexual meaning attracted to members of the OPPOSITE sex, [of, relating to, or marked by sexual interest in the opposite sex than oneself;]
Homosexual meaning attracted to members of the SAME sex, [of, relating to, or marked by sexual interest in the same sex as oneself;]
Bisexual meaning attracted to members of BOTH sexes,[of, relating to, or marked by sexual interest in both sexes;]
then regardless of your own personal opinion, the very nature and definition of the word 'bisexual' means being Bi *IS* an option as it includes both, it does not preclude one or the other.
I could care less what people want to do in their own sex lifes - go ahead and paint yourself green and hang from a trapeze if you want (just may be wise to practice safe sex and use non-toxic paint and make sure the trapeze is well anchored in a ceiling joist.) But, Please, don't mangle the meanings of words! lol