heavy petting 
noun [mass noun]
Erotic contact between two people involving stimulation of the genitals but stopping short of intercourse: they fell to tender embraces that rapidly shifted up a gear to heavy petting...
- I'm pretty sure that is the main reason why the Bible says not to have intercourse or heavy petting until you are married.
- After two weeks of chatting, endless flirting and online heavy petting, it was time to meet.
- If you argue that no premarital sex doesn't mean no petting, well, what's the difference between heavy petting and sex?