OP here, just read all the responses, as soon as I posted this I regretted it and shied away from it. I totally understand/agree with the very harsh comments, but to the 2 people who said I was selfish/had no remorse for the wife, you are completely wrong, that's what I meant when I said I felt guilty (which I did say several times... in the first sentence! what else could I mean that feeling guilty for his wife?). I feel absolutely horrible for her! Thank you all also for the nice, supportive comments. I really appreciate them all even though I haven't replied personally. I feel as thought I couldn't reply to 1 without replying to them all and I don't feel like arguing/debating, so....
I know he cheated before because there were rumours at work and I asked him if they were true, he told me they were. I get the feeling his wife may know/suspect he's cheated, just because of a couple of things he's said about her, but I haven't asked... I might do, actually, it'd be interesting to know. I kind of hope she doesn't.. from what I've seen of her she seems so lovely, happy and sweet.
And as for people asking who came onto who, he came onto me and was inappropriately close with me from when I started etc but he is like that to some degree to every young pretty girl that works there, some more than others (me more than others I guess) the difference is I liked it, so I encouraged it/let it happen/go further knowing he had a wife, so no one is really worse there. my ex before this (the one I mentioned in OP) cheated on me and was cheating on me for like a year with his best friend and then with a girl that he worked with and it was so heartbreaking... so yeah... not sure if that's had an affect on the way I'm acting, but I just feel quite numb/emotionally distant from it at the moment.
I haven't seen him that much since it happened but he still acts the same way with me, flirty and touchy feely and stuff.
As for the whole societal 'who's worse' debate, we did have a chat about that. pretty much everyone at work knows he's a serial cheater but most people still regard him as the lovable charming sweet boss. a lot of the people that work there have cheated/are cheaters, not sure if it's something about the line of work?! it's weird. I know a few people who think he's a dirtbag though, ha. but yeah... I'm sure I wouldn't still be seen as innocent me if people knew (deservedly so)
it's so hard to say no, especially once you've already done it once. but nothing else has really happened since. I still can't stop thinking about him really! we'll see how it goes.
bleh