Tom Riddle (no OOP)

[lee_lhs]

No: HPFGUIDX 65943

I have a question about Tom Riddle (which has probably been answered 
a long time ago already). 

In GOF, the Riddles and their grown up son TOM were killed, who was 
reportedly a very arrogant guy.
Now, given that the father of this Tom Riddle was Voldy "Tom's" 
father, and by the time frame that is suggested, it would mean that 
Voldy's father had an affair with Voldy's mother while already having 
a child and being married?
Or would Tom's father be that young Tom Riddle who was sniffed out 
along with his parents?
And who was that dark haired boy that Frank saw in the night of the 
murderers?

Lee