No, one does not necessarily make a vow of monogamy. If someone has got married using a traditional Christian ceremony, then they have made such a vow (but they still might have agreed with their spouse to vary the terms, afterwards!) If someone has got married in a register office, then unless you were there, you don't know what they promised. At least in Scotland: I was happy to find out that the only thing you have to declare are (a) that you are legally free to marry (b) that you wish to be regarded by the law as married.

That's why I didn't tick more, e.g. "politician who uses their family". OK, if the person breaking the story *does* know that they'd vowed monogamy. I also wondered about "vicar", but decided that's not in the *public* interest. It may be in the interests of the members of that person's church.