The Best Man (2005)

After Olly Pickering and his youth friend and dorm mate Murray graduate, Olly, a promising author, gets a contract and advance, which somehow kills his nerve, even about using urinals. Writer's block forces him to move into professionally successful Murray's Soho (London) spare room and take a crappy job as publishing research assistant. Asked as New York trip friend James's London wedding best man, Oly falls in love at the bachelor party. Alas the flirt turns out to be bride Sarah. Olly would graciously walk away, but sassy Murray keeps arranging, resourcefully, for them to meet and in the process gets on with her bitchy sister. Olly's moral reserve is reconsidered when James admits he isn't monogamous.