Of course you can.
If science fiction writers can write about worlds and times that don’t exist, then you can write about love.
All it takes is a well-honed —- and well-trained —- imagination.
Because describing something you don’t personally know without thinking through how you want to do it, is an exercise in futility and will result in poor writing.
But describing something you don’t know after thinking it through and deciding what you want to say and why you want to say it is the mark of a professional writer of fiction.