Putting this behind a cut because I assume not everyone has seen 2x19 yet. ♥
Okay, you know that scene in "Born This Way" some of us were up in arms about? The one where Dave checks out Sam's tight end, thus breaking the Kurt-centric nature of his attraction? And which Dave later denies doing with the statement to Santana "I was just seeing what jeans he was wearing"?
Well, fellow pirates, in light of the events of "Rumors", let me present to you three facts and a theory full worthy of an aluminum chapeau.
FACT: During the office scene, Dave tells Kurt "I don't know for sure I am gay, okay?" Which fine, could just be more denial, but could also potentially be the truth. In my own head canon, Dave (reluctantly) accepts the fact he likes Kurt but runs into trouble reconciling that fact with his own internal image or preconceived notions of it means to be a guy who likes guys. For my part, I hear a silent "or if it's just you" appended to his statement.
FACT: Sam states that his father lost his job a few months ago and later tells Finn and Rachel that Kurt found out about Sam's situation when Sam delivered a pizza to Dalton. Assuming that this wasn't some surprise pizza party in celebration of a weekend visit, we can reasonably infer then that this event took place sometime before Kurt's return to McKinley.
FACT: Kurt gave Sam some of his old clothes. Now the exchange we saw on camera took place after Kurt's return to McKinley. However, I would like to bring your attention to a few details we know about Kurt. One, that he is very good at keeping secrets, as evidenced by his continued silence regarding Dave. Two, that he has most likely known about Sam's situation since before his return. Three, that while at Dalton, Kurt had a tendency to wear his uniform even when it was not strictly necessary (possibly to match Blaine), thus leaving the remainder of his wardrobe sadly underutilized. Given the juxtaposition of these facts, it doesn't seem unreasonable to posit that Kurt might have given Sam additional clothes at some point in the past. They would probably have been plainer ones, considering Kurt's noted flamboyance when he did go out of uniform during this period.
And now for my insane tinhat theory:
What if Dave did actually have a very good reason to be staring at Sam's jeans? Namely, that he realized they weren't exactly his?
. . .
I await your judgment. *dons tinfoil sailor* \o/
EDITED TO CLARIFY:
I fully believe that Dave is, like, 99% gay. (Ninety-nine because face it, no one is ever 100% anything. We all have our exceptions.) So yes, Dave can and very likely will be at some point in his life attracted to people other than Kurt.
My quibble with the scene in question is related to timing. In my honest opinion, I think Dave is too deep in denial and striving to "act normal" during this time period to openly allow himself attraction to other guys. Was he aware he was doing it? Well, he knew what Santana was talking about right off the bat, so probably. My personal line of thought regarding the event is it was some kind of internal test. "Look, there's the third-gayest-looking kid I know! Am I attracted to him too, yes/no?"
So, no, I don't think that RIB planned this in advance at all. This interpretation is pure tinhattery and intended for amusement purposes only. Pass the tinfoil, please! ♥♥♥