This isn't a good idea. That goes without saying. If she gets dressed up as him, like their friends are reportedly suggesting, it's not going to do either of them any favours. It'll only serve to highlight how homogenous they look. We were going to say 'androgynous' but that would suggest some level of cool. Either way, minimal effort would be required - all he'd have to do is lash on a birrah lippy and he'd be sorted... old photos but you get the jist.
According to a source speaking with HollywoodLife.com (who have the exclusive on this pressing 'story'): "Friends are telling Justin to go out for Halloween as Selena Gomez and to get her to go out with him they think she should dress up as him. They think it would be funny and cute and make a statement that he really likes her." Yep, it would definitely signify that he's been "into her" for a long time. Apologies.
Hang about, the source doesn't stop there, saying that Justin "really likes the idea but is being a little apprehensive as he doesn’t want to dress as a girl, even though it would be Selena... He definitely wants to share Halloween with her though and would love to do a joint costume with her, so this could be the perfect way if they don’t get into a fight before this weekend."
If you're considering gluing yourself to his Instagram this Friday to see if he posts a photo of him as 'Julena', don't bank on one being there. The last thing he posted to his account is quite profound (if a touch hypocritical given the rest of his account's content).