You shouldn't vent your frustration on your ex.
James is attending a get together that his ex, May will also be attending.
James wants to let May know how he feels.
James asks to talk to May privately and proceeds to talk out his issues with their breakup.
James gets drunk and gives May a verbal lashing.
James gets some closure and is able to let go of any lingering hostility towards May.
James is kicked out of the party by his other friends.