Before today, I'd have said no. Causual sex is the reason why I'm here in Longmont right now. Thing is, I've come to realize that being here isn't as bad as I tried to convince myself it was. In fact, once I came to terms with the widespread changes that were forced upon me, I realized that things as a whole are better, and that I'm on a good path now that I'm here. Had I cautioned my roomate not to pick up that girl, I might not have been given a new lease on life, so I guess I have casual sex to thank for that.
So yeah, maybe I would throw caution to the wind and accept the invitation. You just never know where it may lead.