I year ago just after my W filed D and way before she moved out she used to leave her cellphone charging all night in my bedroom. Almost daily there were several short calls from OM at various times of day. I too had felt the distancing and secrecy on various fronts for several months prior to this but trusted her until the D was filed. I felt I had to find out and confirm so as not to misjudge her and I don't regret doing so. I was careful to return it to the state she left it in and never confronted her so she never knew. This was her work cellphone; a few months prior she had asked to add me to my cellphone plan because she did not want to use her work phone for personal calls; if I had I'd have a detailed written trace without having to snoop. Anyway D11 told me some weeks ago that W "does not talk to OM anymore, he's weird and has issues". And as for the instincts and feelings I had a very similar experience as you with kissing her when I left for work and all the other things you list. I tried not to suspect anything before D was filed but one night I had a nightmare she was involved with OM; I guess it was in my subconscious tho' I tried to put it out of my mind.
Me-48, W-38 M14, D11, S7 W filed D 01/07 W had to move out 06/07 Current Thread