I like him and he likes me (but there is someone else)

The title kind of says it all in an incredible nutshell so let me backtrack a little. About seven months ago I started hanging out every day with one of my gay friends (he didn't know I was gay). We'll call him E. We were pretty close before this (I've known the guy for 3 years), but we started spending upwards of 10 hours a day with each other for about a month and got close to the point that people started thinking we were a couple. One day I was hanging out with him at his house and we were sitting next to each other talking about planning a hike and he put his legs on me and before I new it we were in his bedroom having sex.

This is where things get complicated.

I really liked him, and he liked me (I had to ask him why we hooked up the other day, which will make sense by the end of this post...) but he had just broken up with his BF of 6 months who was a mutual friend of hours. He told me we were just friends and thats all we would ever be, but I later found out this wasn't true. He still has feelings for his ex who essentially just used him for sex before saying that he wanted to get back together with his ex girlfriend. He tells me all the time that he still thinks of his ex and how it isn't fair to me for him to be with me while he is still thinking these thoughts.

We continued to see each other and grow incredibly close over the summer and on into the fall, and have now been in an incredibly bizarre monogamous relationship for six months now. We do romantic things like watch sunsets on the beach and talk about our plans for the future (which we don't mention each other but conveniently have the same exact ideas of what we want to do, where we want to live, etc...) and we share everything with each other. If it wasn't obvious by now I really love him (enough to let him go, but I don't want that) and I think he really likes me too, but both of us are to afraid to verbally commit to each other.

He told me a story about a relationship with a girl he had in highscool and how they were basically bf and gf but they weren't official and how she started dating someone and it made him really jealous. I know he said this because that's exactly what is happening with us right now but I feel like I have to continue to wait. However I'm not going to completely wait, I feel like I've stopped living and that this situation is infringing on my happiness so I decided to start dating again.

I met this really nice, sweet, and attractive guy on OKC and on our first date it felt like we had known each other in some previous life (we both thought so). We'll call him K. It worries me that I'm starting to fall for K (I totally am) because I think that if/when E finally shakes his feelings for his ex I would leave the K. On one of our dates last week I couldn't help but imagine and wish that K was E, which is exactly the same thing that has happened between E and myself except he's thinking about his ex. I know how shitty it feels and don't want to do that to someone else, but at the same time I cannot wait (in a strict sense for E).

I brought up in casual conversation with E that I had started dating again and met a really great guy. He immediately wanted to see pictures and seemed happy for me but jealous at the same time. After this conversation we went and watched the sunset from the top of a mountain (his idea) and then went back to his house, had dinner, then had sex... We had a very heart felt conversation after (he always tells me about how he still has feelings for his ex after sex and and gets very melancholy, but tells me its just a wound that needs to heal and he's sure he will get over it). E doesn't believe that gay relationships work because of how much he's been hurt in the past and how he only knows one gay couple that has been together for more than a year.

I'm worried that I might keep dating K just to make E jealous even though that's not why we started dating. I haven't been intimate with K yet, and don't plan to for a very long time. We have a date soon and I'm not sure if I should tell him (I don't think I should yet, but wait until things start to get serious).

Soooooo (sorry for the rant, I'm not out to my family or basically any of my friends and need some advice!) what are your thoughts? Do I keep dating K and show E pictures of us together? Do I write E a letter and tell him that gay relationships do work, and that I want to show him? :help::help::help::help::help::bang::bang::bang: :tears::tears::tears: