Yes. I still feel regret, guilt and shame.
Especially if I attend a church or meet with other Christians.
I get where you're coming from.
Took advantage of an "opportunity" @26 during a time I really felt lonely and desperate (never had an adult relationship).
Later, learned she was a Christian.
I sooooooooooo want to contact her all these years and apologize for being a jerk. But I can't find her name online and I since asked forgiveness from God for that (as well as one other casual incident, only had sex 2X 19-30).
Odd. At that time, felt God had "forgotten" about me (not having a GF from 19-26, no handholding... no hugging... no kissing), but met my first love -- a NEAR-fiance -- just a month later...
Reminisce,
Please try to put it behind you.
Try to understand you're human, like everyone else, and make mistakes.
Don't let guilt feelings get to you when you visit church or other Christian friends.
If you knew their pasts, as you know all too well your own life, you'd likely see many other things, maybe even some things more shocking than what you did.
When I attended church afterward, I didn't let feelings of those earlier incidents torment me.
Guilt is normal and in most cases, like crying, a good thing.
It shows us through our consciences that things are wrong.
However, if you've sought forgiveness over it, please try to move on.
Hope this helps.