Bobby Brown performs on SiriusXM's "Up Close & Personal" hosted by Cayman Kelly (not pictured) at SiriusXM Studio on December 18, 2015 in Washington, DC.

Bobby Brown performs on SiriusXM’s “Up Close & Personal” hosted by Cayman Kelly (not pictured) at SiriusXM Studio on December 18, 2015 in Washington, DC.

*Among all the bombshells in Bobby Brown’s forthcoming memoir “Every Little Step,” the New Edition vet alleges that his late ex-wife Whitney Houston had an affair with Tupac Shakur.

Brown writes in detail about his “bad boy” behavior: his many sexual affairs, with Janet Jackson and Madonna among his alleged partners; and contends that Whitney did her “share of cheating” with “quite a few of the producers and artists” she worked with, including the late Tupac Shakur.

As previously reported, Bobby also confirms that Whitney and her “assistant,” Robyn Crawford, were involved in a same sex relationship.

But he pushes back against allegations that he was a corrupting influence on Houston. He writes that she was using cocaine before he was and continued to use drugs after he had cleaned up.

“Every Little Step” comes out June 13. The Associated Press got its hands on a copy Wednesday and reports the following:

The 322-page book follows Brown’s life from growing up in Roxbury, Massachusetts, and his rise as a child star with New Edition to such platinum-selling solo albums as “Don’t Be Cruel” and his time with Houston and his current wife, Alicia Etheredge-Brown. The book includes testimonials from family members and such professional colleagues as Ralph Tresvant of New Edition and “Don’t Be Cruel” co-producer Kenneth “Babyface” Edmonds.

Brown’s daughter from his relationship with Kim Ward, LaPrincia Brown, alleges in the book that she was in a car with Houston, Bobbi Kristina and Nick Gordon, Bobbi’s boyfriend at the time; when “things got real strange.”

“They all started smoking pot together,” she recalled. “Yes, she (Houston) was smoking with them.”

Brown has feuded with Houston’s mother, singer Cissy Houston, and other in-laws, and alleges a public “orchestration” designed to keep him from Bobbi Kristina and seal his “nefarious” reputation. Responding to “the offensive, pointing fingers” at him, he writes, “Both Whitney and Kristi had been tragically lost on their watch, not mine.”