When somebody meets that special someone else and becomes so enchanted with them that they choose to spend more and more time with them. Time previously devoted to engaging in recreational pursuits with friends and family and co-workers.
"Hey, wheres Phil? He hasn't come out for Chicken Wings and Strippers on Payday for weeks!"
"Out with Vanessa again."
"Again? Uh-oh, do you think its Girlitis?"
"Maybe. His mom said he doesn't even go to darts anymore."