From AMLopedia
What weeny? came from a night in Adam's garage. Liam and Adam were about to leave for a bike ride and were talking with Al in the garage. The conversation went like this:
- Adam: Watch out Liam, he's a crazy man, he'll do anything to get a laugh!
- Liam: What weeny?
Liam had mistaken the phrase "do anything" as "do-weenything".