To be in the act of any form of sexual activity be it flirting or other such things foolish adolescents get up to. If someone were to express their willingness to be kanoodling with someone else they would usally be talking about the person in question CONSTANTLY. An example of this would be:
'nye and izzy were kanoodling at charlottes'
'jade and tom are so gonna be kanoodling at chloes on saturday'