If i get the hint a lady wants me to leave early i will just get dressed and leave. Most times when i do a half hour visit and i finish early i get the vibe my time is up. Without foreplay i cum within like 5-10 minutes of sex so i will take the hint and leave since i dont really enjoy hanging around escorts that dont want me in the first place. No foreplay is a real turn off for me and i cant get into the session.
I would guess most escorts would let u go for round 2 or let u stay for the hour, u will probably most likely know if she wants u to leave tbh.