1.) ready to have sex with a lot less discrimination than usual; girls or guys acting like a dog in heat;
2.) angry, unpredictable and violent; likened to a person acting like chilli is burning their asshole so bad they hate everything in life and may begin killing people at any second
-Hi, my name is Shirley...
-She's so hot in the ass tonight; right after we fucked she left with Joe and Tim followed- go find 'em and you're 4th to hit it Dog!
-your angry ex texting you: please cum over to sleep...cum over as late as you want, the door is open...please just come fuck me however you want, then leave me wanting more and return whenever you like...-dam, you're hot in the ass!
2. Psycho example:
"Stand up right now motherfucker! Come outside and I'll fuck you up right now!" -Dam that guy is hot in the ass.