Not sure if serious?
SOP in my old industry is dentist, 10am apt dentist says to take it easy in the afternoon.. Got to have a root canal... maybe 2...., lots of sharp intake of breath no one will mention it again.
Funerals not a good idea, IMHO. People will ask who, where, when, how....
As for telling the truth, you are already out. Just make your move quick and clean. Don't fuss or drag it out, if its a small industry you may find the jungle drums kick off within a week.
In my old industry it was SOP to only start the process of jumping ship if you were 100% sure you wanted to go as it was usual to get a tap on the shoulder within 48 hours... if you are really close with your DLM then perhaps a quiet chat but I would only do that if they were solid and perhaps on the same page. Any bonus / perf related pay then stay well, well clear till you put your notice in. When I last jumped about half a dozen of us went, incl my DLM. We all knew and we all kind of went together to new company. The regional manager went ape!
Good luck.