Rang him earlier, he is coming over to visit from Spain on Thursday.
DSS will also be staying, originally wasn't having him next weekend but DH and DSS's mum had to re jiggle things and so the pattern (fortnightly weekend visits) had to change.
Any my dad said "oh so it is a regular thing then?" referring to DSS's stay.
So I replied "Yes dad, because when parents split up generally they make arrangements to ensure children have regular contact with their parents", heavy on the sarcasm.
Background - my dad walked out when I was 12 and I hardly saw him between the age of 12 and 18 (when he moved back home to Spain).
Felt slightly guilty, but then I shouldn't really? Not my fault he was such a lousy dad 