Should I meet my 1yo estranged step-nephew?

I have a step-brother who is my age (22). Our parents have been together since 1999, so we have a good relationship. While I love him to death, I will be one of the first to admit he's not always been the best at being responsible.

Background:

He has a 3 year old son who calls me "Aunt ______" and who I have known to be my nephew since before he was born (we'll call him Luke). When my step-bro (we'll call him Nate) graduated from h.s., he proposed to his gf of 6 yrs. Shortly after, they found out they were pregnant & he changed his carefree ways and was ready to settle down & step up. When Luke was about a year old, his mother decided she wanted no part in being a mother or wife and left to pursue a life of drugs. Nate was so in love and so naturally, he was heartbroken. He really stepped up and he is a wonderful father to Luke. That part he has done right.

However, he jumped into a rocky rebound relationship after his longtime love left. This relationship only lasted about 2 months. A few months later though, he got a call saying her baby was his. He was skeptical since they hadn't been together long, but after its birth and a paternity test, it was found that the boy was his. This boy ("Branden") is now a year old.

Nate pays child support for Branden, but they don't have a relationship. He has seen his son on several occasions, but the mother ("Sammie") won't have any visitations without her there--which is understandable, but she causes drama the entire time of the visit with Nate's new fiancee, and Sammie always leaves angry, saying that Nate will not see Branden anymore.

Luke does know Branden is his brother, but they only interact at cousins' houses in instances where they are both invited to a party or something like that. My step-sister (Nate's sis) has babysat Branden at Sammie's house, but that's about the extent of their relationship.

What's going on now:

Sammie reached out to me on facebook a couple of months ago, and, not wanting to be rude, I accepted her friend request. Yesterday she saw my status about our brief trip to their state to visit (6 hrs away). She asked if I wanted to meet Branden.

I don't know what to answer. This is a really awkward situation. Nobody ever talks about Branden. He's not my "real" nephew so I feel like I don't "owe" him anything--but then again, neither is Luke, and nothing stopped me from having a great relationship with him. I feel like I shouldn't go behind Nate's back to meet Branden and I don't want to betray my relationship with his new fiancee.

I would not be going to Sammie's house to meet Branden. She would bring him to my dad's. They really don't have much to do with him, so it's very weird. I do not want awkwardness between me and my family over this. I just feel like this is a really awkward situation to put myself into. The child is 1, so it's not like HE WANTS to meet me. And to be perfectly honest, I do not feel a void if I don't meet him. I know that sounds really bad, but it's true. I have Luke and two actual nephews and an actual niece. I've been doing fine without him. What would be the benefit? I live 6 hrs away and don't get to visit often. What kind of a relationship can I really have with Branden if I live 6 hrs away and no one else in the family interacts with him?

Don't give me the "RIGHT" answer; I know what that is: meet the child and make a relationship with him. Tell me what YOU HONESTLY THINK YOU WOULD DO if you were in this situation.

Then, if you said for me to meet him, do you think I should bring him a Christmas gift? If I meet Branden, I would feel weird bringing Luke one and not Branden. But again, I feel awkward and I don't know the kid. And how weird would that be if I did bring a gift, didn't meet him, and my dad/stepmom never saw the kid either?