Can also be when a guy licks out a girl when on her period and he kisses her after licking the pussy and transfers the period blood back into her mouth.
Only a real whore would attempt this.
2. You are fucking disgusting!
1. Never try a rainbow kiss, you will throw up
2. I know, me and this whore did it last night and we threw up in eachothers mouth !
"erm, no, I don't think we should actually."
Now when the guy/girl has blood/cum in their mouth, they kiss eachother.