How long should I wait till he files for a divorce.

Home town that I have know of for a long time. He's 3yrs. older than me. We got to talking and he opened up to me that he was in a loveless marriage and sleeps on the couch for the past 2 yrs. No intamacy what so ever. We started seeing each other and love being with one another. How long do I wait for him to file for divorce?