I think this is correct, but it seems off. I'll take any help! My mother is deceased so I can't list her as a host.
Mr (my step dad first and last name)
Requests the honour of your presence
at the Nuptial Mass at which
Clara (my full name)
and
(DF full name)
son of Mr and Mrs (father in law first and last name)
will be united in the Sacrament of Holy Matrimony
on Saturday, the (date) of December
two thousand sixteen
at half past one in the afternoon
(Church information)