Committing public displays of affection in a gross and overly loving manner. This can include kissing, touching, tickling, secret whispering, private knowing glances in the company of strangers, friends and family. It also suggests a total lack of awareness at the discomfort of those witnessing the creg.
Noun- a creg
verb- to creg
plural- creggan
"Did you see Chris cregging with his girlfriend"
"Ye, she was kissing his neck and grabbing his joint!"