Nipples that are the same color as the flesh around them prior to arousal. Post arousal they become a different shade making them easier to see and locate.
Man the girl I was with last night had Rudolph nipples!
the act of lighting your playmates nose on fire on christmas and them forcing them to suck your dick while the nose is still lit.
i got the best rudolph the red boned reindeer last year from my girlfreind
When someone is going down on you and you start to get your period
"Dude! She gave me a Rudolph's Nose!” “Sick dude!”