Hot Line Dling is the definition of eastern europe guys who want ding-ge-ling their balls sack into a hot tub full of macaroni with some special sauce made of pieces of hot shit(90c) and bacteria. It's usually used as a term of respect to a very hot woman who got spitted on. You spit on the hoe, slap the hoe and then do the what's so called 'Hot Line Dling'
"Jesus woman I'm going for the Hot Line Dling on yo azz"
"Damn bruh this gurl so tight ima Hot line Dling da shit outtah her"
"Thiss bitchh gott mee craaazzzyyy ima hot line dling her ass"
One could state he is singing "I know when that cell phone ring, that can only mean one thing". It just so happens that in this song he is referring to a booty call as is affirmed by the mention of "late night when you need my love"
The term itself does NOT mean "booty call". Your hotline could bling any time of the day and it could be your boss or even your mother.
"Yo dude are you ever gonna answer that? I can hear your hotline blingin from the other roomover and over ."
"Nah man its my Lil sister, she's buggin me for a ride but I cbf right now."