Ignoring the wink, Marcus rolled his eyes lightly but smiled slightly as he said, "You already do listen to me talk about Quidditch all day long." Which wasn't all that surprising, given their profession and the fact that they were teammates. And perhaps he was focusing more on the words themselves than what what they implied, because there was no reason for him to read into anything - no matter how much he might have wanted to, though he didn't always admit that to himself.
Although he nodded in agreement at the comment about relaxing, he was a little wary when Roger's expression changed, because that was the face that usually spelled 'trouble' in some capacity. This instinct turned out to be correct, and Marcus turned his head away to hide another blush, even as he shook his head, a little flustered, and said "I am not answering that." Proper Pureblood upbringing aside, he didn't quite understand how people - not just Roger, because there were plenty of others who fell into this category as well - could be so open about sex-related things. To him it was something private, even when it was between two people, and the topic had a tendency to make him vaguely uncomfortable.
He wasn't entirely sure how to respond to the first half of that statement, so he limited his answer to, "Yeah. And it gets more tiring the older I get." For Merlin's sake he was turning thirty in a few months time, a fact he didn't like to be reminded of. It was practically ancient in a sport that recruited teenagers, and his age was yet another reason Marcus pushed himself so hard to maintain his competitive edge. No one needed to be getting any ideas about replacing him quite yet.
Marcus caught himself looking a little too close at the spot where Roger's teeth met his lip, and immediately forced his eyes to shoot upward and meet the other man's eyes again. Waving off the compliment with a vague motion of his hand, he said, "I think you're not giving yourself enough credit. It's a team sport, and I wouldn't be scoring goals if you weren't there to get the Quaffle to me in the first place." Pausing to take a sip from his butterbeer, he then continued, "I agree with you about Moran, but I think we can compensate for any shortcomings that might arise there."