What is the ruling of the Shari'ah regarding a love relationship between a married man and a married woman, involving kisses and touching, without reaching the point of fornication, and what are the consequences of these actions in terms of sin?

You have fallen into a great sin with this forbidden relationship and its practices with a married woman, and by betraying your wife. You must immediately sever ties with this woman and cut off all paths leading to her, for touching a non-mahram woman is forbidden, so how much more so what is greater than that. This act is an abomination that could escalate to indecency, for which the punishment is stoning. Fear Allah and be content with your wife. If you can leave the country, then do so. Increase in righteous deeds, avoid places of temptation, and accompany your wife.