Whitney Houston's toyboy lover has written an X-rated song about their sex life.

R'n'B singer Ray J - who, at 27, is 17 years younger than Whitney - also slates her ex-husband Bobby Brown in new song 'Boyfriend'.

Lyrics include: "Is that your wife, is that your shorty, well I'm her boyfriend. I think the problem is you don't beat it right. Making love is cool, just pull her hair sometimes."

Despite Jay's jibes, Bobby - who has a 15-year-old daughter with the 'I Will Always Love You' singer - insists he doesn't care who his former spouse dates.

In his book 'Being Bobby Brown: The Whole Truth and Nothin' But', he said: "I'm aware of the fact that Whitney had been seeing Ray J, a very young R'n'B artist who is most famous for being the little brother of Brandy, the multi-platinum singing artist and TV star.

"Their relationship doesn't bother me. She's open to see whoever she wants to see, just like I can see who I want to see. I know the age difference between her and the little guy is almost 20 years, but each to his own."

In his book, Bobby claims Whitney introduced him to cocaine and addresses the rumors about her being bisexual.