But sometimes when I speak with him he says things*(emotional) like I wish it was me & you together right now...etc,
You're kidding me right? In the recesses of your mind, which are being overridden by your emotions, you KNOW you're being played. This dude is trying to get into your panties, MM2. Nothing more.
I don"t think he is a mean spirited person, or he just wants to ruin my marriage because he knows I am happy, I just thinks he regrets that we never really had a fair chance of making things work back then.
The most pertinent point you make in the quote above is "I don't think . . ." You obviously "feel," and substitute that for thinking. Believe me, he isn't putting that much thought into it. When the opportunity presents itself, he's blowing a few kind words up your skirt and waiting for you to reveal the prize.
There is a reason why people come in to our lives, maybe to help them or vice versa, we might never know the true nature until later on in life.(not saying that this is the case here)...but my question is why?.
Ah! Let's muddy the waters, confuse the point, and dodge responsibility behind the false cover of philosophy. He came into your life because you let him. He stays in your life because you let him. There's no deeper meaning here.
The conflicting thoughts in your head are the result of you letting this man meet some of your emotional needs. The conflict is not in thought, it's between thoughts and feelings, the feelings being the result of chemicals released in your brain due to contact, both mental and physical, with this man. Pavlov and his dog. Nothing more. Your thoughts -- the ones telling you to get the hell away from this guy -- are correct.
Stop it, MM2. Stop it now. Confess to your husband and cut your ex out of your life forever. You're playing with fire, and you're gonna burn down everything and everyone around you.