How about "it's not an affair. because she said she doesn't DO affairs. besides, I told you yesterday that I was through with this marriage."

M60
H52
D20
M14 yrs
OW-old gf from 1986
bomb-5/18/08
H filed for D-9/10/08
D final 4/24/09
xH remarried (not OW) 2012