Prince William jokes about changing nappies

Prince William was spreading the love on Valentine's Day with no one, but two, royal engagements.

Both however focused on The Duke of Cambridge's pet cause - men's mental health.

While visit a workshop and support group for new dads, held by Future Men, the father-of-three made some animated comments from his own experience, as he watched one attendee practise changing nappies on a doll.

"It's never straight forward," the 37-year-old warned.

"The hardest thing is the buttons...and then the wrong leg ends up there...," he trailed off, clearly talking from experience.

The father to Prince George, Princess Charlotte and Prince Louis also spoke to a number of dads who had been through the program and asked how the transition into reality went.

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Again, the Royal left the group in fits of laughter with an animated anecdote.

Prince William also discussed the importance of self care when you become a new dad. 

At one point the Prince was seen holding one of the dolls, presumably as part of one of the Future Dads' exercises.

Earlier in the day, the Duke went to meet those behind Pall Mall Barbers, in London's West, where he spoke to members of the international organisation known as Lions Barber Collective.

They work to assist the mental health sector by training barbers to recognise signs of depression and mental health issues and raise awareness for suicide prevention.