45 per cent of Aussies are dirty, dirty cheaters. Not only in the bedroom, but in the loungeroom, while they are on the Xbox, on their smartphone at the gym, on the way to work on the train.
The nature of this betrayal is deep, long lasting, and is damaging relationships. I'm sorry to be the one to break this to you.
Your partner is likely to be sneaking episodes of that series you're watching together without you.