OP Are you a 5 bikes “I’ll have my cake and eat it” sort of chap?
Intimacy is very important, but trust more so. Come clean, snap it off and shack up with your new partner. If your wife finds out and tolerates; she is a doormat. For her and your sake untangle it.
Sounds like you’ve found the right person for now; is this shiny shiny syndrome with t*ts or proper love? When the sparkle has worn off is she still so great? I’m talking snotty, puking, yada yada yada….and still the same in your eyes, or is she an alternative relief to normality?
If it’s good, pursue it; you could be hit by a bus tomorrow. But give the people involved some respect. Maybe she’s not into you either (based on what you say about intimacy) and you’ll be releasing her from the role of wife/mother she has now solidified in?
Good luck, you’re going to need it!