Panel 1: As the two of them walk to the gym, Mike gets all smiley and stupid when tells Gordon that he sees his 'friend' Allyson up ahead; this doesn't make Gord happy because she's will Peter "Mr Cool" Kent.
Panel 2: Mike and Gordon take turns being the narrator when Mike points out that they aren't going to the dance and Gordon (rather unnecessarily) states that they're going behind the football bleachers.
Panel 3: Since he's been watching 'those' movies because Elly's attention has been diverted again, Mike is rather eager when he tells Gordon that they should follow them. Gordon sets up the punchline by asking him what he thinks they're going to do.
Panel 4: Since his favourite film is probably "Prom Night At Horny High" (the bland-name equivalent to "Porky's" from Rick Mercer's "The Industry"), Mike tells him "It's Valentine's Day, isn't it?" because he expects to see them going to at least second base.
Summary: What he's going to see instead is Peter trying to get the two of them into the party mood by pretty much becoming Fred Goddamned Sanford and swilling down Ripple. This leads to Gordon being treated like a great big hero because he did the human thing instead of the Patterson thing.