We only have our tups in with their ewes for a month, or at most 6 weeks, in late Autumn. The rest of the time they are in with the meat boys across the road, well away from the ewes. That way we know exactly when the ewes will lamb without having to scan, and without the risk of tups bossing the ewes around at inappopriate times, especially when they are lambing.
If it is important to you not to have out of season lambs then it would be best to keep your tups separate except at your chosen tupping time.