What is i only see him once a week?

"I only see him once a week" means that the speaker meets or hangs out with someone only one time per week. This could either be a friend or a romantic partner. It is possible that the two do not live in close proximity or have busy schedules that restrict them from meeting more frequently. Alternatively, the relationship may not be very strong or may be in the early stages, so they are still getting to know each other.