ANY sex - oral, or further. French kissing. Touchy feely in the back seat. Doing a Bill Clinton and sticking a cigar in her pussy. Basically, any time you're involved in trying to get laid by someone other than your partner.
Getting any sexual pleasure from someone other than your partner. That obviously includes sex (of any kind) but it also includes kissing in a way intended to make you feel tingly. Kissing your brother/sister hello when you see them isn't cheating. Planting a big wet one on someone you'd like to get into bed but you can't (because it's cheating) is also cheating.
Basically, if you wouldn't do it in front of your partner, don't do it.
Or if seeing your partner do the same thing would make you uncomfortable. Generally not that tough to figure out what is right & wrong in a relationship. Just turn things around and see how they feel.
Miss Karen henderson of woodhorn road Ashington Northumberland is a cheating slag