Is my husband acting weird?

I just want to state in advance that I have nothing against homosexuals whatsoever, I’m just a little confused and unsure how to feel about this particular situation...

Today, we spent christmas at my in-law’s, for the first time since my husband and I have been married… just a little background info- it’s a small town so these people have all known each other their entire lives… So my husband’s (step)sister’s husband happens to be a very very close friend to my husband… (since they were born, according to him)…
anyways… throughout the entire day they were, like, cuddling… and stepsister’s husband was caressing my husband’s hand and thigh… at first I sincerely thought it was a joke and they were just being funny. Well, they weren’t. He says they’ve always been like that because they’re like brothers and grew up together.

Here’s the thing, I come from a SUPER dysfunctional screwed up family so I have no idea where to draw any lines to be perfectly honest but for some reason this is just not sitting well with me!! I couldn’t tell you why… it just feels… idk… weird?? I sort of brought it up to my husband when we got home, at first to see if they were just being funny or if he was trying to mess around but he basically told me that wasn’t the case him and i joke with each other a lot so i did make a few jokes about it with him just to gauge his reaction and the first few times he just kind of went with it and tried to laugh it off and then got super defensive about it and i really could not tell you why this is bothering me so badly but it is.

i guess my question would be: is this normal behavior for two grown men (in their 40s) if they grew up together and are super close? orr is this weird?.. he’s not like that with any of his actual brothers or other relatives so it just rubs me the wrong way. maybe i’m just reading too much into it… i have a tendency of doing that at times… opinions please…?