Needless to say, the business of living interferes with the solitude so needed for any work of the imagination. Here's what Virginia Woolf said in her diary about the sticky issue: "I've shirked two parties, and another Frenchman, and buying a hat, and tea with Hilda Trevelyan, for I really can't combine all this with keeping all my imaginary people going.
Take your time and make sure the person who you do intend to have sex with is someone you deeply love and care about, and make sure you get to know them as much as you can, and make sure by having sex you don't compromise your character.