If you are looking at the marriage at the Fleet on 8 January 1721/22, it is recorded differently in two notebooks.
One source (RG 7/5) shows the marriage of Alexander (no other name) of Northfleet, near Chatham, Kent, and Ann DARSY, spinster. The other (RG 7/29), on the same date, shows the names as Alexander ELLIOT, bachelor, of Northfleet, and Ann DARSLY, spinster.
Some of the Fleet notebooks are very rough and are known to have errors. But I can't see any hint of the name LAFON (or variant spelling) in either of these two records.