You are right (under the argument made by the left). Who says love has to be romantic/physical love? How about platonic love? Brotherly love? Since marriage is no longer about procreation and family, all bets are off.
If we aren't supposed to care about what other people do in the privacy of their own bedrooms (leftist argument), then we shouldn't care about what they DON'T do in their bedrooms, either. And if "love is love", then any kind of love should do: best friends, family, etc.