Liam Payne would find it ''difficult'' to write a song about his son.

The 'Strip That Down' singer and his girlfriend Cheryl welcomed son Bear into the world 12 months ago but the 24-year-old star has admitted the tot hasn't inspired any tracks on his upcoming solo album.

Speaking on 'Front Row Japan', he said: ''He wasn't born during the production of the album, so there's not a song about Bear on it.

''It's difficult because Bear is the best thing I've ever experienced so it couldn't be a boring song, it wouldn't be something that was done easily.''

However, Cheryl, 34, is expected to sing about Bear on her own upcoming new album.

Producer Naughty Boy previously revealed she had penned a ''very personal'' and ''meaningful'' track about becoming a mother.

He said: ''Cheryl has got back in the studio just after having a baby and it's still very personal, but she is a real artist and a perfectionist.

''She does up to 12 hours a day and I just feel that shows how ready she is.''

''I can't tell you the name of her track but it has been influenced by her son Bear.

''It has got more edge than anything she has done before. I feel it is going to be very special and meaningful.''

Meanwhile, Liam recently revealed he feels ''very fortunate'' to be in a relationship with someone in the same industry.

He said: ''[I'm] very fortunate that I partnered up with someone who is ... very understanding with what I do. Because I don't think anybody else could take it.

''It's difficult, obviously: having someone else who's so high-profile in the media pushes everything that I do to another level, and I think it's weird.''