The difference between monogamy and vegetarianism here is that monogamy requires a binding commitment from another person. Thus, the inability to make a binding contract is a problem for monogamy but not vegetarianism.
Monogamy just means that you do not seek more than one sexual or romantic partner.
You can be monogamous while your party isn't. Whether this would suit you is a matter of personal preferences.
Or, two partners can be monogamous even if they have no legal mean to bind themselves to.
Another month has passed and here is a new rationality quotes thread. The usual rules are: