Hi Amy
Whilst the condom on the tongue seems like a good idea to avoid Hep A/E from rimming, your lips are still in the region.
Much of the tongue is keratinized (toughened) and so fairly resistant to viruses.
But if any bodily fluids flow over your condom covered tongue, it once again poses a risk to you.
Absorption may take place from your lips, gums or at the back of your mouth.
And so I would say that a condom covered tongue may make rimming a little less distasteful for you
but I don't think it will offer the safety you want. May be the dam would be better??
Like Benny, just looking out for your safety.
PM me if you'd like to know anything more.
MM
PS Hope you're in Dublin in 2/3 weeks