So, so, so true!
When I was living at the Catholic student center, I shared a simple, innocent goodbye kiss with my now-fiance.
It was so overwhelming I literally stumbled the ten feet to the Blessed Sacrament Chapel and collapsed right in front of the tabernacle.
You misunderstand me. Whether or not the pair can stop before intercourse is not the issue. I am a virgin, and so is my fiance. Obviously, we’re able to stop ourselves despite having shared (IMO, unfortunately) some rather passionate kisses.
It isn’t necessary to have intercourse or even engage in illicit behavior such as mutual masturbation for the act to become a grave matter. Kissing is enjoyable. Passionate (as opposed to affectionate) kissing is enjoyable because it is arousing. Purposely engaging in an arousing activity when one cannot complete the act could in and of itself be a mortal sin, whether or not completion is intended, unintended, or even considered.
Self control is not the issue, not in spite of but because of the fact that we are not animals. We are capable of rational thought. With that capability comes the responsibility to exercise discretion so that our actions do not lead us to sinful thoughts. We are also instructed not to purposely expose ourselves to the near occasion of sin. For most people, passionate kissing constitutes a near occasion of sin.