Disclaimer: If the Potterverse was mine, things would have gone very differently. That said, many thanks to JK Rowling for letting us play in the world she created. It's one hell of a sandbox.
"POP!"
Dean and Seamus Apparated into an alley behind a defunct flower shop in Upton Park. Dean was nearly vibrating with excitement, and even the football-naïve Seamus found his enthusiasm infectious.
"Let's go ahead and get inside so we can find our seats and get some food and maybe watch some warm ups and-"
"Breathe, D," Seamus laughed as his boyfriend dragged him toward the gates.
Once inside, Seamus found Boleyn Ground to be not too unlike a Quidditch stadium. There was a pitch in the middle with goals on both ends, and seats were crammed into every available space around the field. He looked at the man sitting next to him and stifled a chuckle.
Dean had on a West Ham jersey, a West Ham cap, and West Ham face paint, leaving no doubt as to who he was supporting today. He'd kindly loaned Seamus an old T-shirt for the day. Seamus had no intention of returning, invoking boyfriend privileges. Dean's left hand was shoved into what he called a "foam finger", which Seamus thought would catch on quite well in Quidditch. The players were still warming up, but Dean was already yelling at them and the people seated around him with excitement.
Seamus found the actual sport quite boring. A bunch of men got together and kicked around a Quaffle-sized ball for an hour and a half with very few goals- less than five the whole match!
What Seamus loved was watching Dean watch the match. His facial expression changed with every pass, every possession change, every shot; so much so that it was difficult for Seamus to keep up with how he was supposed to be feeling. When West Ham scored and broke the tie in the final minutes of the game, Seamus found it slightly more exciting. However, he was far more interested in the way Dean was jumping around, spilling his popcorn and hugging the man sitting on his other side, whom he'd never met before today.
Walking out of the stadium, Dean slung his arm around Seamus's shoulders.
"So, what did you think?" he asked the Irish man. "Would you do it again?"
Seamus looked up into Dean's face, reveling in the light, the joy he saw in his deep brown eyes. After the war, it had been so long before he saw Dean look this way again. These days, he took every opportunity he could to appreciate it. If some deadly boring football match could make him feel this way…
"Hell yeah! That was great! I'd totally be down to see another match!" Seamus said without an ounce of deceit.