A coma is a state of prolonged unconsciousness, which can be caused by one of many, many things. Many people believe that even if a person is in a coma, s/he can still hear you if you speak to him/her.
"Hey there, Grandma. I hope you wake up from that dreadful coma soon. I miss your cooking--"
*Nurse leaves*
"I'm going to spray some whipped cream up your asshole, and THERE'S NOTHING YOU CAN DO ABOUT IT! Haw haw haw!"
The period after one starts a newrelationship, during which one loses contact with one's friends because one is devoting all one's time to one's significant other. Usually preceded by "boyfriend" or "girlfriend" for clarity.
I tried to get Dave up in here but he's still in his girlfriend coma.