If your friend is a New York Mets fan, get them a Mets jersey. If they're a Philadelphia Phillies fan, a Phillies jersey would be a fine gift.
But what if, against all odds, they're equally passionate about both teams? What would you get them then?
If such a person even exists, given the fierce rivalry between the teams, you might want to stop by London.
Fans visiting the area, which is promoting the Mets-Phillies series in the United Kingdom this weekend, noticed some peculiar merchandise for sale which had the logos of both teams on them.