Replying to Help me choose a jacket size (I'm an indecisive dumbass)

Yeah so I like this jacket, can't decide on sizing though, I mix it up with baggy and slim pants when riding.

Help me make the decision NS, I'm lost without your approval!

Which size is better, should i exchange the bigger one for the smaller one or stick with what I got?

+K for helpful answers.

Oh yeah and ignore the goofy face, I hate photos and selfies are even worse!