Aye man means: A Geordie expression of emphatic agreement or affirmation - essentially 'yes!' or 'absolutely!' The 'aye' is the standard Geordie/Northern English form of 'yes,' and 'man' functions as a general. There is no real cause for parental concern; it is descriptive vocabulary rather than risky behaviour. If your teen uses it, context will usually make the intent clear. A short, curious question about where they heard it is usually all that is needed to know whether to follow up.