I got a call from a recruiter from another firm and they gave me a tentative offer that is overall better than my current job. The company was looking for somebody with my skill set and they were quite eager to proceed to the next phase (face to face interview). However, I decided to stay with current company before going to the next phase, because I don't want to go through learning and getting-to-know phase again and prefer the known good before the possibly better.
We are a small company without any HR department and very flat hierarchy. I work as a senior specialist (~ 10 years experience) in a relatively small domain. I have been in the company for about a year, but in my field it doesn't really matter who you work for, because the work is always the same. I work with my superior quite often and we engage in small talk as well. Should I mention it to them? Is there any harm or benefit in that?
I also asked for a tiny benefit before the recruiter contacted me. Everybody was OK with it, but things are moving a bit slowly (if at all). I wonder whether telling my boss about the recruiter's interest might expedite my request or sound like pushing instead.
EDIT: It seems that people tend to answer a different question. It's not about bluffing. It would not be wise to ask for something based on having an offer that I don't have. But I don't have it, because it was my decision. That is what I wanted to tell my superior, that I have decided not to pursue this opportunity.
2nd EDIT: Thanks everyone. I accepted the most up-voted answer, because it is the most likely scenario. It's a thin ice situation with high risk (supervisor might not understand it) and minimum gain. But I have decided to give the bounty to the answer that deals with the complete opposite and also likely scenario. In conclusion, it seems that loyalty will be either questioned or used against me.