Confused about my bro in law's ex girlfriend?

My brother in law got broken up with from his girlfriend of 5 years. My boyfriend says that they seemed to have been over for a while before the break up. Immediately after the break up she started posting photos of her and her new boyfriend on instagram. My brother in law started seeing this other girl and it's nothing serious, but they're going out a bit.

The thing I find weird is, the ex is coming with us all on a trip to another state for a family wedding. She also traveled to see us for the fourth of July (she lives in a different state than us).

I asked my boyfriend if this was awkward for them at all but he said no and that they're just trying to be friends. I just find it weird that she has a boyfriend but is traveling with the ex and his family to another state for a wedding.

I guess because they used to live together during the 5 years... but still. Does anyone else find this weird like me? Or is this sort of thing normal between exes? How is her boyfriend okay with this?
Confused about my bro in law's ex girlfriend?
Add Opinion