I have done something that is really immature and shit for a 30 something year old woman, I am feeling really ashamed 
To give some back story, I met a man online a few months ago and we dated for 5 months. During this time it was extremely intense, he was extremely complimentary towards me, talked about our future together, saw each other very regularly, I introduced him into my home. We also had sex without a condom which is something I am very meticulous about but I really felt I had a future with this guy (I made sure he showed me proof of an up to date STI test prior to this of course).
It turned out that he had still been going on the dating site in which we met throughout our 'relationship' and had been picking up women for sex. At least 5 that I know of. It seems to be his game that he picks up women on these dating sites and has a string of us on the go at once. When I confronted him about this as he had led me on, as well as putting my sexual health at risk, he rebuffed saying 'well I have to see who is the best shag before I settle don't I?' I found this out 2 weeks ago and didn't talk to him.
So here is the part where I did something really shit. My friend and I were sharing a bottle of wine on Friday evening and I was upset about this whole situation. In our giddy state we made a fake online dating profile using her pictures to lure him in. We then arranged for the two of them to go on a date on the Sunday evening. Come the Sunday evening, he went to the arranged meeting spot and we then messaged him from the profile saying that 'she'd seen him and decided not to approach him as he was far uglier and heavier than his pictures, and he should use more up to date ones to avoid tricking women.' Yes it was immature and I feel really stupid now.
Today he called me out of the blue and told me of the experience he had over the weekend and that it knocked him for six. He told me that he feels terrible for treating me so cruelly as well as the other women, and he is no longer going to do any online dating as his confidence is in tatters and he didn't realise he could feel this shit about himself.
I feel even more terrible for what I have done now. Should I confess and tell him that it was me and my friend? Or keep quiet about it? What he did to me and the other women was really shit but I am generally not a vengeful woman.