just kidding... but seriously
When someone says something that they want to admit but not really but they still think it and they kind of want you to know that they are serious
Freddie: dude that girl is hott... I want to hit that shit
Chris: dude that's my sister
Freddie: I'm just kidding... but seriously
Chris: dude that's my sister
Freddie: I'm just kidding... but seriously