<human>: Condense the text into a few key points

We decided it would be safest to wait until marriage, primarily because we didn't know how the relationship would pan out. That was four years ago. Now, it kind of seems inevitable because we have pretty much done everything except sex and we get close to penetration then stop. I don't masturbate because she considers it synonymous with cheating. I just don't see the point in waiting anymore, we're both horny and want each other, and it would be a nice release. She doesn't understand my reasoning. How do I explain it to her? Am I being a jerk for wanting to have sex?
<bot>: Girlfriend of four years wants to wait for sex, but I don't see the point in holding out any longer.