"It came out that Blake didn't know that Ryan and I had a make-out session when I was 19," the actress, now 37, told PEOPLE Saturday at the celebration for Soleil Moon Frye's new entertaining guide, Let's Get This Party Started, in Beverly Hills. "She did know, actually. She reached out to me via email to help her with a birthday present for Ryan!"
Hart, who just headed back to the West Coast to film the new season of Melissa & Joey, reveals the tidbit in her memoir, Melissa Explains It All: Tales from My Abnormally Normal Life, to be released later this month. She isn't surprised by the focus on the racier parts of the book – in addition to her kiss and tell, Hart discusses partying and drug experimentation in her early 20s – but says some media coverage has exaggerated and misconstrued her stories.
"I expected that – people think it's a tell-all, but it's not," she clarifies. "I wasn't going to write a book and leave out my mistakes. I'm going to include everything. Some chapters are heartwarming, some are silly. I meant for it and wanted it to be mostly funny."
As she told PEOPLE in September, “I've led a very blessed life and that’s reflected in the book. It's very honest – there are shoutouts to everyone who has molded my life, both good and bad. I'm excited to see what people think.”
As for the ways her stories are spun, Hart recently advised fans to take it all with a grain of salt.
"Whatever you may read about me these next few weeks, keep in mind the outlet that is reporting. Also remember, I was 20 when Sabrina started! I'm cracking up right now at how ridiculously wrong some 'journalists' can get a story. Oh well," she writes. "For the record, I'm not denying my mistakes; I wrote it in my book. But the details have been messed with! And by the way, my 'party life' is one chapter in a book about my entire life."