Closest I got was after an attempted bait & switch several years ago at a well known house that moved from karrinyup Rd.
After protesting attempted switch, started 1 on 1 fs session, then about 10 min in she said switch girl is not busy and is bored & horny, would I like her to join!
i said I had only brought $ for the single girl session, so she said ok I’ll see if she horny but no extra $. Answer yes

so FFM for single $.
Then 15 min later 3rd girl in house finishes her client, pops head in the door, sees it going off and sits on the end of the bed to watch. Starts playing with herself so I ask if she’s up to join in too.
Faster than a speeding bullet FFM is transformed to FFFM, with all 3 focus on me rather than FF play




.
Definitely a fond memory!!!