Heterosexuality and homosexuality are subsets of allosexuality (sexual attraction and behavior towards others). Autosexual acts such as masturbation are not allosexual and so do not contribute to heterosexual or homosexual identity.
Example: A lesbian trans woman might masturbate using her penis, even though she has no attraction to penis-havers, just because she happens to be equipped with one.
Example: A heterosexual cis woman might masturbate using her vulva, even though she has no attraction to vulva-havers, just because she happens to be equipped with one.
Heterosexuality and homosexuality are subsets of allosexuality (sexual attraction and behavior towards others). Autosexual acts such as masturbation are not allosexual and so do not contribute to heterosexual or homosexual identity.
Example: A lesbian trans woman might masturbate using her penis, even though she has no attraction to penis-havers, just because she happens to be equipped with one.
Example: A heterosexual cis woman might masturbate using her vulva, even though she has no attraction to vulva-havers, just because she happens to be equipped with one.