Relationship Question

So, question.

Background: You are a single gay man, in redneck territory, and decide to get a profile on a dating website.  And you meet and chat via email with a guy who lives a few hours away, and never meet, and he flakes off and leaves you hanging.  Then, months later you meet, and end up dating someone else.

Situation: You have really no experiences in the gay world, and commit to someone who knows this.  And, is very set in his ways of being in a relationship. Your BF is very accommodating to your learning curve, even though it bothers him.

Dilemma:  So after 1 and a half years, the guy you were interested in before you meet your BF, adds you to FaceBook.  You don't add him in front of your BF, but rather, on your way home to sleep before work. (As you are in basically a long distance relationship, and only spend a few days at a time with your BF in the city).  So, you go to a family member's house (as you do not have the Internet at home), and add this former suitor.  You don't mention this to your BF, who has to ask you about it, as he saw the news feed update 10 hours later on his own FB profile.  And, you don't even make an effort to communicate with him.
Until one night, while online, you chat him on FB, while your BF is making dinner 2 feet from you.
And be completely blase about it.

Question: So, as the BF, how would this make you feel?  Do you let it go, as you know that this other guy is suppose to be in relationship?  Do you open dialogue, to find out how your BF is feeling-as in, what motivation he had to not just add him, but to finally chat him up?  If you were the BF who did this, would you 1-have even added this other guy? 2-after 2 years of no contact, randomly say hi? 

Anyone, feel free to comment, reply, answer, give opinion. 
Interested in hearing feedback.
Thanks.