I don't know what to do!! Is it something more? HELP?!?!?!?

Ok.. so I'm 27. I'm a paralegal at a local law firm that my boss took over from his dad. A little over 5 years ago I moved to the city I live in now (not really big either) to be with my fiance (we'll call him Jon) who I then married. We met in college... Anyway, 4 and a half months ago, I decide to take my husband dinner to his work since he was working late. He's an architect. So I walk to his office a little after 8 and his door is cracked open.. I hear some noise and when I look in, he has his istant bent over the desk screwing the hell out of her. He sees me, I tell him not to bother coming home till I move out. So the next morning I go to work and tell my boss (the attorney I work for.. we'll call him Alex) that I'm going to have to quit and I'd only be able to work a couple more days.. I explain the situation and he makes me an offer that I take him up on. He's also handling my divorce proceedings. Before I tell you the offer I'll tell you why I took him up on it. I had no real friends here that I could turn to. They were mutual friends of me and my husband and he's known them longer.. So I wasn't going to make them pick sides. Second, my family lives 7 hours away.. I hadn't kept in touch with hardly any friends and its a small town hurting for jobs. So, the offer was: he would let me move in with him (yes he's single) till I found a place to go, rent free. He and I have become friends since I started working here 4 and a half years ago so I thought nothing of it. So I've been living with him for a little over 4 months now and my husband (soon to be ex) is starting to spread rumors about me saying I was cheating on him with Alex all along.. People actually believe him. Partly because Alex is only 8 years older than me and he's nice on the eyes (he looks just like a young Alec Baldwin).. Alex just laughs it off.. He says that people will say what they want but as long as we know the truth it doesn't matter.. Being roomates, we hang out and go out to eat with each other.. Last night we went out to eat and saw a couple of Jon's friends. They kept staring and giving us looks.. Alex and I had both had a couple gles of wine and I make a comment about them staring so he says something along the lines of 'Well lets give them something to stare at' and he leans over and kisses me. I was stunned but I kissed him back. Never had I thought he would do that. I never would have thought I'd kiss him back. We're just friends. I thought. Then he kissed me and I kissed him.. When we went home last night we went to bed (in our separate rooms) and in the middle of the night he comes in and wakes me up. He tells me he's sorry if he made me uncomfortable but it was just something he felt like he needed to do. He didn't elaborate, he just kissed me on the forehead, told me goodnight and went back to bed.. I don't know if he meant he felt like he needed to do that because they were staring at us or if it was because he just wanted to kiss me. I don't know what to do now? I know why I kissed him.. He's as good as men come. Sweet, honest, dependable, gorgeous lol and smells amazing :) . But I haven't ever thought of him as anything but a friend. At least not until that. He should be home anytime now (I had today off) and I don't know what to say to him.. Any idea how to approach last night? Or should I pretend it didn't happen? Why do you think he kissed me at dinner??