LMAO....My man Indigo, boy have you brought back memories for me.
You asked a question and I will give you an answer right from your wife's twin sisters mouth (my x). You provide security to her that the other man does not. I would venture to guess (no matter what she has told you) that back in October the OM called things off for a bit to work on his marriage. Hence she went to you begging for you to come back (her security blanket). Hence she has you for security and the OM is there too. For the OM....The "working on the marriage" thing is a ploy that his wife was getting suspicious so he had to chill it for a bit.
As for her current actions towards you....They are to keep you pacified, nothing more.
Yes...I know it [censored]. Your current story matches the last 6 months of my marriage exactly. The real question is what are you going to do? Right now you are whirling in the emotional winds....I suggest calming that wind down a little bit before you do anything. Right no you are reacting to everything and control nothing (including yourself).
Be strong Indigo....You have a choice coming up regretfully.