Fairmaid,
Sales is not a common surname in Fermanagh. Curry is. Sales is not a common name in Ireland generally. In the 1901 census, there’s only 37, a mix of Presbyterians (ie Scottish ancestry) Church of Ireland (could be Scottish, English or Welsh) and RC. However if you include variant spellings eg Sailes, Sale etc, the numbers increase slightly. Enniskillen was a garrison town so it’s possible Thomas was a soldier stationed there, who came from some other part of the UK, and that Bridget Curry was a local girl he met. But that’s just a speculative guess.
Curry is predominantly, though not exclusively RC. It could be a mixed marriage.
I can’t see any Sales deaths in Fermanagh 1864 to 1870, so suspect parents must have died prior to 1864 when the statutory death records begin.
If you think the children were RC, or that the marriage was RC, then the parish baptism and marriage records are on-line and can be searched on the Ancestry site. (As I understand it, free for the month of March). If they were Church of Ireland, then the Enniskillen early records were lost in the 1922 fire and so you won’t get any baptisms. Statutory birth registration did not start till 1864 so the births are all too early for that. Could be hard to trace them if they were Church of Ireland.
I searched for a non RC marriage for Thomas and Bridget. They start in the stat registers in April 1845. Did not find one. If it was an RC ceremony then you may find it on the Ancestry site, in the parish records.
I searched for references to Sales on the Fermanagh Gold site but did not find anything that might relate to your family.
http://search.atavus.org