Sexay joined the World Wrestling Entertainment in 1997, going by Brian Christopher, and began to compete in the fledgling light heavyweight division. Taka Michinoku defeated him in the finals of a tournament for the Light Heavyweight Championship. In mid 1998, he started teaming up with Scott "Too Hot" Taylor to form the tag team of Too Much.
For a while, when Sexay was known as Brian Christopher, his father Jerry Lawler didn't publicly acknowledge that Brian was his son, although after Paul Heyman revealed that fact on RAW, Jim Ross (Jerry's broadcast partner) always hinted at it. A notable example of this was during the Light Heavyweight Championship match at Judgement Day 1998 between Taka Michinoku and Christian, when Jerry Lawler reveals that he wants to see more of Brian Christopher - to which Ross replies "Haven't you got some baby photos?".
In late 1999, Brian and Scott adopted the ring names Grandmaster Sexay and Scotty 2 Hotty, returning after a hiatus, and later becoming faces. Their tag team was renamed Too Cool, and were later joined by Rikishi, becoming three of the company's top fan favorites. They enjoyed an immensely popular run as Too Cool, as well as success in the tag team division, defeating Edge and Christian in May 2000 on Raw to become the Tag Team Champions. They were even occasionally involved with top-card feuds, notably being enemies to the McMahon-Helmsley Faction and their associates, such as The Radicalz, Edge and Christian, and T & A. The trio's run ended in late 2000 when Rikishi was revealed as the man behind the wheel of the car that hit Stone Cold Steve Austin at Survivor Series. Shortly after, Rikishi turned heel and turned on his teammates.
While Scotty was sidelined in 2001 with a broken ankle, Sexay formed a short-lived tag team with Steve Blackman and was later released from the company.
In April 2004, Sexay (as Brian Lawler) was signed back to the WWE roster as Jim Ross's last act as WWE talent scout. He only appeared in 4 matches, one against Kane, one against Wavell Starr, one against Christian, and the last one against Garrison Cade. He was later released after only one month with the company. Prior to his release, Lawler was scheduled to take part in a Battle Royal for the number one contender for the World Heavyweight Championship, but he was replaced by Maven.
On the March 14, 2011 episode of Raw, Lawler returned to the WWE as a heel in a segment between Michael Cole and his father, Jerry Lawler, where Brian would side with Cole, saying that he felt that Jerry never cared for him and that he was ashamed to be his son. Lawler indirectly agreed, telling Brian that he was a bigger screw-up than Charlie Sheen. Lawler also told Brian in the following exact words "just the fact that you would associate yourself with a jackass like Michael Cole tells everybody here tonight what kind of a person you are".
Sexay returned to the WWE on January 5, 2014, appearing on the "Old School" edition of Raw and reuniting with Rikishi and Scotty 2 Hotty to take on 3MB in six man tag team match. His team was successful in winning, turning Lawler back to a face in the process. He made an appearance on NXT Arrival in February 2014 as part of Too Cool in a losing effort as mystery opponents to The Ascension, who defended their NXT Tag Team Championship.