Possible Clues:

• Breach of privacy, perhaps
• Encroachment
• Interloping suitor's drunk inside pub
• Gatecrashing suitor drunk in bar
• Nun is involved with trio making encroachment
• Uninvited presence
• Meddling isn't in our diverse characters
• Something entering undesirably
• A. E. Housman deplored that of a 'comma on p four'