Should I fire my love?

OK, bad idea dating at work. Worst idea falling in love with suborinate. Throw in keeping the relationship a secret from staff and coworkers, dinners in far away places, sex and breaking most of the HR rules. I've been with company 15 yaers, she's been here 6 months. How do I sit down with her and say: I love you. You're fired. Are we still on for dinner tonight? It's actually not funny. The pressure of keeping secrets, and pretending not to be close at work is hard.