Weird insta comment...

so my bf met up with his brothers and they took a picture all together and one of them posted it on instagram.. one girl (who I don't even know and never heard of) commented "aw you cuties 😘😘".. considering that only one of them is single, i found it really flirty and weird...? i mean also the one who posted the picture is even engaged to someone ...  who is she 👀 i asked my bf if anyone came along with them, he said no... so I'm just really confused.