This is why people say not to fool around where you work. You say you knew that.
There is a power balance between bosses and assistants. If you go for it, as an assistant, you set yourself up... most of the time.
I suppose once in a while it works out - Leona Helmsly? But also on occasion with people who aren't primarily users.
On some rare occasions, the connection is serious, just fine between grown ups.
But the power balance situation is prime for abuse.