Is my friend's boyfriend being flirty in a friendly or teasing manner?

So there are four of us. Me and my bf, his friend and his girlfriend. We are all friends and we hung out two days ago.

Let's call the male friend, M. This chelloveck:

a) groped his girlfriend's ass in front of me, while watching me to see my reaction, and afterwards, he laughed and told his protesting gf that it was okay for me to see because "I was a girl."

b) drew attention to his hoo haa (lol) by making comments about its size, and even standing up and starting to unzip his pants. (His gf stopped him, haha.) I looked away because all four of us were in the room and I didn't want drama.

c) when I said that I rolled joints too loose, he called out, "You're loose!" Then corrected himself, while his gf was complaining about something, "Actually, Asian girls are supposed to be tight..."


I already have my boyfriend and I have no idea what to make of his friend behaving this way... He's either just a goofball or he's naturally flirty with every girl he meets. What do you guys think?