Feels

I've been with my boyfriend for almost 3 years. We've had a rough road, including cheating, insecurities, and many other things (all him). I had his baby 7 months ago, but I don't feel like I love him anymore. 
I got a new job a month ago. One of the managers there clearly has feelings for me. And every time he looks at me, I get butterflies. 
Someone give me advice. Part of me wants to see what happens with said manager. The other part doesn't want to hurt my boyfriend like he's hurt me. 
I just don't know why I feel all hott and bothered, every time manager looks at me. 
*also* I am 22. Boyfriend is 26. Manager is probably 30ish. 
WHAT IS WRONG WITH ME?!