People who say things like “my body, my choice” and “same-sex marriage is about being able to marry whomever you love” usually don’t mean anything like what the slogans say. For example, no one who consistently believes in bodily autonomy could oppose organ markets or support the War on Drugs. If someone thinks that same-sex marriage is good because it lets people marry whom they want, they should also support the legalization of polygamy and consanguineous marriage. Seeing as support for organ markets and polygamy is much lower than the number of people who say the words - and the active opposition to these policy changes by pro-choicers and same-sex marriage supporters - it suggests to me that support for legal abortion and same-sex marriage comes not from the stated principles but from the desire to treat those who benefit from the policies as in-groups. “My body, my choice” doesn’t mean “my body, my choice”, it means “Women should be treated as an in-group”. “Consenting adults should be free to marry whomever they love” doesn’t mean that people should actually be able to marry the person they love, it means “LGB people should be treated as an in-group”.
This is a bit frustrating to me because I believe in the literal meaning of these slogans. Rick Santorum once said that the arguments for same-sex marriage apply to the legalization of polygamy as well. They do. This is a feature, not a bug.