Hello pawb!
It’s been a while since I was on the forum, but I was hoping someone could help me out.
My now-husband and I eloped earlier this month in the US, and we are planning to send out bilingual announcement cards (even to my US family, surprising unsuspecting Americans with Welsh is one of my favorite passtimes. 
)
He is from Pwllheli, and I have only ever spoken (and texted) informal northern Cymraeg with everyone I’ve met up there. Most wedding announcements/invitations I’ve seen in the US use very formal English, and I wonder what y’all think about using formal vs informal, “standard” southern vs our authentic northern dialect.
The English part will say something very close to: “Charles & Shaun were married the 1st of December, 2021 in a small ceremony with all of you in our hearts.”
The Cymraeg I’ve come up with (but have not run by any native speakers yet) is: “Charles & Shaun wedi priodi mewn seremoni fach ar y 1af Rhagfyr 2021 efo phob un ohonoch chi yn ein calonnau.”
Is it completely unheard of to use “efo” in a written, formal announcement? Should I go with “gyda” instead even though nobody we’ll send this to uses that word? I should mention that my husband is very, very gog and he often pokes fun at me when I use a “southy” word without realizing it, and I’ve even taking to using some on purpose to poke fun right back at him 
Please feel free to be as pedantic as possible! I know that there is no “right” way to speak Welsh but I am curious as to the norms and customs, and unfortunately most of my time in Wales has been covid time so I have not seen many formal invitations or announcements to model ours from.
