"fuck girls who choose to have sex" is not at all the same as what you originally said, "sluts who can't be faithful to their men."
The statement "sluts who can't be faithful to their men" openly shames sluts, aka women who choose to have sex with multiple people, or in this case, more than one person. At a show? It becomes worse because it's justifying the pop punk bros who hold that belief and telling the women that they should be guilty for making somewhat unorthodox choices about their sex lives (key word: their).
I think this post does a very nice job of summing it up (and yes, that sly dig is probably about TSSF): [url]http://thehotelyear.tumblr.com/post/29182544437/beccaonthecoast-i-am-literally-speechless/url]
The songs can be weakly brushed off as personal venting, but that comment? No chance in hell.