Brown, who remains on probation for his 2009 beating of then-girlfriend Rihanna, is notorious for his violent temper. In addition to his brutal attack of Rihanna, now 23, Brown angrily threw a chair at a dressing room window of Good Morning America's studios in March 2011 when Robin Roberts asked him about his history of domestic abuse.
Following the incident, Brown left a message on Twitter saying, "I'm so over people bring this past s**t up!! Yet we praise Charlie Sheen and other celebs for there[sic] bulls**t." It was deleted moments later.
Lohan, who gushed that Brown "killed it" during Sunday night's MTV VMAs, is famously unstable as well. She's known more for her partying ways, courtroom couture and trips to rehab than she is for her acting.
The Mean Girls actress, who appears to have taken a liking to Brown, has been romantically linked with a slew of celebrity bachelors, including Wilmer Valderrama, singer Aaron Carter and actor and Chapter 27 costar Jared Leto. Lohan split from disc jockey Samantha Ronson in April 2009.