zew, I've been following your sitch closely, as it has been fairly similar to mine; WAW in an A - but still lives with me, mind you in separate rooms - and while she didn't deny the A (nor confirm it, either) at first - I confronted her once I had evidence to confirm it.
It seems like your confrontation had more of an impact on your W, mine seems to have dug in and is more committed to the A than before.
I do agree they need to feel a loss, and don't dispute stepping in. Seems like you handled it fairly well. Good job!
-Pluto
H: 29 W: 27 No Kids
Together: 12/04 (9 years) Living: 02/09 (5 years) Married: 06/13 (11 months) ILYBNILWY: 01/14 Separate Bedrooms: 01/14 Discovered Affair: 02/14 (On-going) W Moved Out: 06/14