Can we ease up on the bantering of the OP please.
While you may or may not agree with his suggested attire. There's no need to belittle his choices, tell him how to manage his relationship, or even suggest not going to the match.
I see a lot of things at matches, and in everyday life, that I wouldn't wear. But as long as it's not harming me, it's none of my business.
To the OP, wear what you want. The club won't turn you away as long as you're appropriately covered. If you and your girlfriend enjoy dressing up, go for it and enjoy your day.
Hope you have a great time!