Is my hubby bisexual?

I am a straight, white female, in my 40's and am married to what I thought was a 'straight', white guy in his 40's. We have been married for 4 years and this is both our first marriage.

My hubby has been exhibiting strange behaviour since I met him. The only thing that comes to mind is that he may be bisexual. Jeff (not his real name) is a quiet, shy guy who loves to read, doesn't participate or watch sports or drink alcohol and has no desire for friendships.

These are the strange behaviours:
1. It might just be a guy thing, but he refuses to bond emotionally with me. Everything I talk about he either doesn't agree or says the opposite, so there's no way for us to bond. (It wasn't like this when we were dating)

2. In his spare time, he reads (a lot) often through meals and anytime we are together and before bed. He rarely converses with me.

3. He has zero to little interest in sex with me and when we do, he is boring only wanting to do the same thing everytime. I have chatted many times about my likes/dislikes - but he never tells me what he likes, he just says "I dunno" - how can you not know what you like sexually? In the beginning, he was very scared as though I was his first girlfriend and he couldnt perform for months. But over time things worked out and we had some fun.

4. One day I needed to clean out my computer because it was slow and discovered 100's of pictures of women in tight clothes and porn sites.

5. He often asks when I'm going out, how long will I be and when will I be coming home? He says he asks because he's trying to have interest in my interests. But he never talks "about" my interests - just time frames.

6. He watches and looks at men every where we go. I've never seen him look at women. He says he's looking to see if he "knows" them. But my hubby has zero fiends, doesn't belong to any clubs or associations, volunteers and he works out of the country. How would he know anyone?

7. When he's driving, we often drive by known gay cruising areas in our city. I never have reason to visit these areas.

8. He abruptly leaves the house to go shopping or run an errand and always says he will be back in an hour. One time he abruptly needed to go and fill our bbq tank (we seldom use the bbq) ... but he didn't take the tank with him.

9. He usually dresses in clothes that are too big or just unfashionable. Last summer he was very interested in losing a bit of weight, finding jeans and shorts that "looked good on him", getting new glasses and shoes.

10. He often tells me that he has shaven down there, all the way around to the back - firstly, why does he need to tell me and just ... why?

11. I have tried talking to him about all of this and more, but he denies it all but was never shocked or concerned that I confronted him with possible cheating. If I wasn't cheating, I'd be shocked that my hubby thought this of me. One time, he was angry and said "you have no proof" ...

So, I just want to know what all this adds up to - then I can start to figure out the next step. What do you think?