According to Guiness & thereabouts
 a Mr. Gavin Mo Nates
of no fixed abode, Albion
holds the current World Record
for the longest ever yawn
.
It lasted 8 years,
174 days,
16 hours,
23 minutes
& 5.7 seconds
& yes, he was fed with tubes
- top that
....
Post Scriptum:
There was a lady in Norway
that came within a fortnight
but that's still the target