How are muslim guys with dating? Guy that is interested in me has now quit his job because I've been given a male assistant to help me at work?

Me and the guy that has now left worked closely for about a year and he grew attached to me i think. He was then put on another project in another office 2 months ago but Friday gone he took one look at the new guy and words were exchanged.
I'm working closely with the new guy and training him a lot and we are getting on well.

The guy i used to work with asked to speak to my boss apparently he said 'thank you for everything but I can't do this anymore" and just left (minutes after meeting the new guy)

Can some Muslim guys be very territorial and posessive? The guy that was interested in me that left had posted heartbroken quotes several weeks before he left.
How are muslim guys with dating? Guy that is interested in me has now quit his job because I've been given a male assistant to help me at work?
Post Opinion