I don't believe your W threw it away for one night of lies. I think that night was a symptom and not the cause.
I do believe however that she does appear unwilling to address what it is that makes her feel so unsexual etc. I do believe she loves you, and as you know, I have often wondered if the ONS was down to her trying to see if her sexual side still worked and whether it was you that was the problem, (i.e. she was not sexually attracted to you), or whether she had just lost that side of her feelings generally. I think you have your answer by the fact that she is still there. IMO, I don't think she feels sexually towards anyone. However, she is happier leaving it that way than addressing it.
If it were me, I would be looking at this as a sex starved M and whether one could kick start things and if not, looking at just what a deal breaker that was. I do not beleive the ONS is ANY indicator of her love for you. That is just my personal opinion, as someone who has actually gone through periods of not feeling sexual at all for whatever reason. I now know it is important to push myself through that because once things start rolling along I really enjoy it.....and actually I will become the one with the HD. But it is a big thing to actually get to that point. That is where I believe your W has problems. For whatever reason she won't push herself that extra mile.
If you can't live with that then you need to move on. But in many ways she does show her love for you now - she just won't do it sexually.
Saffie me 46 H 46 M in 1986 D20,D18,S16,D13 H's A 01/05 to 07/06 H recommitted to M 07/06 renewed vows 09/06 Going from strength to strength