You have probably thought about this a few times, or at least heard others talk about it. Or asked yourself “Is my Jealousy acceptable with this?” As it always is with jealousy, there is no book that tells us the rules of what you can and cannot do in a relationship, It’s completely determined by your own relationship’s boundaries. 
It’s well discussed whether it’s okay, or not to look at others when you are in a relationship, whether you are together with your partner or not, when you look at others.
Now my clear answer for you comes, and I’ll hope you listen very well.
Everybody is looking at people from the opposite sex! It’s completely normal and simply okay.
If you believe that you don’t do it, then ask yourself just one more time, because I’m sure you do. There’s a very high chance for your partner to do the same, even if it’s a jealous partner you have. It doesn’t need to be every day, but just sometimes. Now when we are at it, ask yourself whether you
Is it okay to become Jealous if my partner looks at someone else?
1