Relationship woes

I've been with my boyfriend for three years now, I'm 20 years old by the way so I'm still quite young. Anyways there's this new guy in work and we've been talking everyday and flirting with eachother and I think I may like him.. I feel so guilty but at the same time I love my boyfriend but I really have fallen hard for this guy in work.. I don't wanna make a permanent decision on a temporary emotion but what do I do?.. I'm set in my ways with my boyfriend also which is hard. What do I do?!