It had all been very carefully thought out.
With the exception of the sensor light that had had you moving a lot faster than anticipated (read: running), you had been in and out without a sound. Excluding, of course, the pants and wheezes that you had made while legging it back to your place. All you had to do now was wait - and tell Christine, obviously, because there would be hell to pay if she found out from Leonard.
Because you knew she was out and wanted to speak as little about it as possible, you wanted to leave what you had hoped was going to be a simple message that put her in the know without revealing too much. Your brain had another idea.
"Hey Christine. Hey. I, uh, I did it. That thing we were talking about, you know? It's done. I know I said I wouldn't do it, alright, I know, but I was bored and may have had a couple glasses of that wine that you so conveniently left at my place and one thing led to another. Maybe a few glasses actually. Tell him it was me and I will end you. End. You. Besides, you point the finger at me and I'll point mine right back at you."