What do these guys really want?

-Ok so I was seeing one guy(A), nothing serious just for 鈥渇un鈥?(we are around 30 y.o), then he got a gf and I haven鈥檛 heard from him for a year as he just disappeared. Now his friend (B) is trying to talk to my best friend on facebook (!) calling her pretty and babe, while he has a gf for 4 years. Funny thing is that we all met on vacay few yrs ago and his friend (B) was avoiding us, especially me as we made out with him in vacay while he having a gf and lying to me that he is single.

So recently he(B) was kinda stalking my sis wanting us all to hang out...So we decided to meet just as friends, So we all met at lounge hang out and had a great time, laughed a lot , they were very nice to us brought their friends and introduced the to us and they wanted us to continue partying at their place. They definitely were a bit flirty . the day after he texted that he had an amazing time

They didn鈥檛 bring their g.friends and they don鈥檛 know about all this, now it seems they want to keep hanging out so I don鈥檛 understand what the hell do they want.... they have many friends, So what鈥檚 the deal of these guys hanging out with us while leaving their girlfriends behind, plus we all neighbours...they seem to be happy with their long-term girl friends.

That鈥檚 really weird and feels like there are some intentions from their side otherwise why would they...after so long ago and they act as they were single....