My husband had a affair, how did he get away with it? He didn't.
He was put on a training course for 3 weeks for work very close to home. He had a set time to start/finish. The first day I knew something was up as the course was "full of old biddies" when I knew it wasn't the case (nature of job/training) he started leaving earlier and finishing later, dressing in his posh clothes, styling his hair, wearing aftershave, wearing new pants.
Then befriending a woman on fb with no mutual friends, as soon as I saw that post appear on my wall I knew what he was upto. But I bided my time and started asking lots more questions and started taking note of his actions.
He never used his mobile and it was now glued to him.
He never once mentioned her funily enough, but his new best mate "phill" was spoken about a lot.
Like other posters have mentioned, she wasn't all that. Lots older than myself, not attractive but she threw herself at him. She was happily married,
Funnily enough we have renewed our wedding vows, why? Well he broke them so we needed to fix that. Have I ever intended to renew them any other time? God no, not something we would of ever done.
He asked me after we renewed our vows if we ever had to do it again, I said no if you ever cheat on me again your history so we won't need too!
I honestly believe if these cheaters carry on behaving completely normal, cover there tracks and no increased contact with the OW/OM and don't change in themselfs they will and can easily get away with it. Especially if the other partner really trusts them.