See if your other half, the hostess, is wearing an evening dress similar to a little dress.
If so, wear a suit.
Choosing the right suit will not make you look fat, but will improve your image and mental outlook.
Suits are divided into formal clothes and casual clothes.
Choose something casual, if girls don't dress up grandly ~
Or if you really didn't choose any suit, you just chose something similar to a suit.
Just don't be too different in color and style.
In a word, you'd better discuss it with your partner. It looks more appropriate and harmonious to wear together as a host.