It is not adultery if you have already separated If you engage in a sexual relationship with someone while you are still legally married, it is technically adultery even if you and your former partner do not live together anymore and are no longer emotionally or physically in a relationship.

Can you sleep with someone else while separated?

If there is no petition before the court, if one or indeed both partners have met someone new and wish to pursue a relationship having sexual intercourse with someone else does amount to adultery. The answer is regardless of whether the sexual encounter happened after separation or not, the parties are still married.