According to sex therapist and relationship coach Jacqueline Hellyer there is nothing to be worried about.
Hellyer told Whimn.com.au that calling your partner "Daddy" during sex is just another type of role play - a perfectly normal concept within the boundaries of a safe relationship.
"Role plays - and in particular, power exchange role plays - are a very safe way for people with strong personalities to let go.
"You often find that women who like to be 'submissive' in relationships - like the kind of women who'd call their partner 'Daddy' in bed - are actually pretty high-powered in their day-to-day lives. Engaging in this role play is their way of letting go and giving in to vulnerability."
Hellyer believes the term "Daddy" is symbolic to the qualities a father possesses - "caring, supportive and assertive".
"We tend to come up with things that make us safe. The father figure is a very safe person, so it's an ideal way to express your sexuality and experience pleasure."
She also said the healthiest relationships are often ones where sexual fantasies can be explored safely where there are clear boundaries and communication and trust are evident.