Taurus men subtle signs + leaving his gf?

Okay, here goes: (if you don't want to read, the question is at the bottom)
I'm a Cancer woman. I met this Taurus about 6 months ago and we immediately clicked. Maybe not so much conversationally (I was pretty shy) but our body language did all the talking. He was really charming and I thought was attracted to me. (input please?):
He would always find ways to stay close and always tried to start conversations. Every time he??d make a joke he??d look over to see if I would laugh and when I did he??d try very hard to make and maintain eye contact.

We saw each other on a regular basis with our group of friends for a while but later our group of friends had gotten much smaller, making for more intimate time between us..
He really started to pay close attention whenever I??d speak (even when I??d mumble) and he??d always stand/sit SUUPPER close to me. Once he stroked my arm while telling me a story and to be honest I nearly jumped out of my skin. He would always address all of his stories directly to me (instead of the whole group) and tried to condense the conversations to just us. We always shared playful looks and he??d talk about the stories I had told him to his friends. He also always show up in my regular hangout spots. He beckoned me to stay in touch when he went on a trip (which he asked of none of my other friends) and told me he wanted to see me when he got back.
I don't know, things seemed really postive until I found out he had a girlfriend. The kicker? I didn't find out from him. I found out from one of our friends. He's never even mentioned her. They have been dating for a year and from what I??ve read, I heard Tauruses are extremely loyal.
Here's the thing. I am ABSOLUTELY AGAINST any and all flirting to get a guy away from his girlfriend. I hate all meddeling and dirty tactics to break up relationships. If I would have known, I would have never reciprocated and stayed away. I stopped hanging around the group for a few weeks now and I just have this question:

If Taureans are so loyal why is this one acting like he doesn't have a girlfriend? I'm not going to pursue him or try anything fishy, but what are the chances that he will, on his own merit, break up with his current girlfriend for a possible relationship with me?

I think if he's not courting you then its non of your business to know. He is loyal to his gf but Of course he still appreciate woman specially if they are beautiful 🙂... women also appreciate the beauty in a man right? We still act friendly when were approach by very handsome man right? But we don't have feelings for them. And Tauruses are friendly. Hmmm and ... i think its just a man thing also,,, men's testing if a woman is easy . I guess... I guess. So all you gotta do is never assume. we crabs arent like that. I guess Taurus are also attracted to cancers ... I have many Taurus colleagues who shows very predictable attraction with me, but I don't assume unless he approach me and show more SURE signs.

Why didn't you ask him if he had a girlfriend?

jeeesh...

Honestly if I were you (I'm not you but if I were you) I wouldn't entertain the thought of him leaving his girlfriend.

What I would entertain is the thought of that if he can be this slick with you behind his girlfriends back then surely if he dumps her and you become the new girlfriend he'll do it to you too. He'll never mention you and flirt behind your back incessantly with someone else.

To not mention the girlfriend and instead lead you on (for me) means he has no self control, poor boundaries and overall not good boyfriend material.

The risk of getting heartbroken increases when a man has poor boundaries and lacks self control.