'The Big Bang Theory' in trouble due to ego hasslesLos Angeles, Jan 1 (AZINS) Massive egos, jealousy and falling ratings are the reasons why "The Big Bang Theory" will reportedly wrap up after season 12.

Tensions exploded following rating disaster in the series' season 11, and that may lead to the show shutting down, reports radaronline.com.

"Many of the cast members have gotten swelled heads. Some of the other actors aren't happy about it," said a source.

Despite their big salaries, some cast members were "itching" to exit the series, the source added.

Parsons got himself a gig on "The Big Bang Theory" spin-off "Young Sheldon", on which he serves as narrator. It reportedly annoyed his "Big Bang" co-stars Kaley Cuoco and Johnny Galecki, who portray Penny and Leonard Hofstadter respectively.

Meanwhile, Galecki allegedly was "silently simmering" over Parsons' status as TV's highest paid star, earning $27.5 million a year.